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How to Cite Sources

Here is a complete list for how to cite sources. Most of these guides present citation guidance and examples in MLA, APA, and Chicago.

If you’re looking for general information on MLA or APA citations , the EasyBib Writing Center was designed for you! It has articles on what’s needed in an MLA in-text citation , how to format an APA paper, what an MLA annotated bibliography is, making an MLA works cited page, and much more!

MLA Format Citation Examples

The Modern Language Association created the MLA Style, currently in its 9th edition, to provide researchers with guidelines for writing and documenting scholarly borrowings.  Most often used in the humanities, MLA style (or MLA format ) has been adopted and used by numerous other disciplines, in multiple parts of the world.

MLA provides standard rules to follow so that most research papers are formatted in a similar manner. This makes it easier for readers to comprehend the information. The MLA in-text citation guidelines, MLA works cited standards, and MLA annotated bibliography instructions provide scholars with the information they need to properly cite sources in their research papers, articles, and assignments.

• Book Chapter
• Conference Paper
• Documentary
• Encyclopedia
• Google Images
• Kindle Book
• Memorial Inscription
• Museum Exhibit
• Painting or Artwork
• PowerPoint Presentation
• Sheet Music
• Thesis or Dissertation
• YouTube Video

APA Format Citation Examples

The American Psychological Association created the APA citation style in 1929 as a way to help psychologists, anthropologists, and even business managers establish one common way to cite sources and present content.

APA is used when citing sources for academic articles such as journals, and is intended to help readers better comprehend content, and to avoid language bias wherever possible. The APA style (or APA format ) is now in its 7th edition, and provides citation style guides for virtually any type of resource.

Chicago Style Citation Examples

The Chicago/Turabian style of citing sources is generally used when citing sources for humanities papers, and is best known for its requirement that writers place bibliographic citations at the bottom of a page (in Chicago-format footnotes ) or at the end of a paper (endnotes).

The Turabian and Chicago citation styles are almost identical, but the Turabian style is geared towards student published papers such as theses and dissertations, while the Chicago style provides guidelines for all types of publications. This is why you’ll commonly see Chicago style and Turabian style presented together. The Chicago Manual of Style is currently in its 17th edition, and Turabian’s A Manual for Writers of Research Papers, Theses, and Dissertations is in its 8th edition.

Citing Specific Sources or Events

• Declaration of Independence
• Gettysburg Address
• Martin Luther King Jr. Speech
• President Obama’s Farewell Address
• President Trump’s Inauguration Speech
• White House Press Briefing

Additional FAQs

• Citing Archived Contributors
• Citing a Blog
• Citing a Book Chapter
• Citing a Source in a Foreign Language
• Citing an Image
• Citing a Song
• Citing Special Contributors
• Citing a Translated Article
• Citing a Tweet

6 Interesting Citation Facts

The world of citations may seem cut and dry, but there’s more to them than just specific capitalization rules, MLA in-text citations , and other formatting specifications. Citations have been helping researches document their sources for hundreds of years, and are a great way to learn more about a particular subject area.

Ever wonder what sets all the different styles apart, or how they came to be in the first place? Read on for some interesting facts about citations!

1. There are Over 7,000 Different Citation Styles

You may be familiar with MLA and APA citation styles, but there are actually thousands of citation styles used for all different academic disciplines all across the world. Deciding which one to use can be difficult, so be sure to ask you instructor which one you should be using for your next paper.

2. Some Citation Styles are Named After People

While a majority of citation styles are named for the specific organizations that publish them (i.e. APA is published by the American Psychological Association, and MLA format is named for the Modern Language Association), some are actually named after individuals. The most well-known example of this is perhaps Turabian style, named for Kate L. Turabian, an American educator and writer. She developed this style as a condensed version of the Chicago Manual of Style in order to present a more concise set of rules to students.

3. There are Some Really Specific and Uniquely Named Citation Styles

How specific can citation styles get? The answer is very. For example, the “Flavour and Fragrance Journal” style is based on a bimonthly, peer-reviewed scientific journal published since 1985 by John Wiley & Sons. It publishes original research articles, reviews and special reports on all aspects of flavor and fragrance. Another example is “Nordic Pulp and Paper Research,” a style used by an international scientific magazine covering science and technology for the areas of wood or bio-mass constituents.

4. More citations were created on  EasyBib.com  in the first quarter of 2018 than there are people in California.

The US Census Bureau estimates that approximately 39.5 million people live in the state of California. Meanwhile, about 43 million citations were made on EasyBib from January to March of 2018. That’s a lot of citations.

5. “Citations” is a Word With a Long History

The word “citations” can be traced back literally thousands of years to the Latin word “citare” meaning “to summon, urge, call; put in sudden motion, call forward; rouse, excite.” The word then took on its more modern meaning and relevance to writing papers in the 1600s, where it became known as the “act of citing or quoting a passage from a book, etc.”

6. Citation Styles are Always Changing

The concept of citations always stays the same. It is a means of preventing plagiarism and demonstrating where you relied on outside sources. The specific style rules, however, can and do change regularly. For example, in 2018 alone, 46 new citation styles were introduced , and 106 updates were made to exiting styles. At EasyBib, we are always on the lookout for ways to improve our styles and opportunities to add new ones to our list.

Why Citations Matter

Here are the ways accurate citations can help your students achieve academic success, and how you can answer the dreaded question, “why should I cite my sources?”

They Give Credit to the Right People

Citing their sources makes sure that the reader can differentiate the student’s original thoughts from those of other researchers. Not only does this make sure that the sources they use receive proper credit for their work, it ensures that the student receives deserved recognition for their unique contributions to the topic. Whether the student is citing in MLA format , APA format , or any other style, citations serve as a natural way to place a student’s work in the broader context of the subject area, and serve as an easy way to gauge their commitment to the project.

They Provide Hard Evidence of Ideas

Having many citations from a wide variety of sources related to their idea means that the student is working on a well-researched and respected subject. Citing sources that back up their claim creates room for fact-checking and further research . And, if they can cite a few sources that have the converse opinion or idea, and then demonstrate to the reader why they believe that that viewpoint is wrong by again citing credible sources, the student is well on their way to winning over the reader and cementing their point of view.

They Promote Originality and Prevent Plagiarism

The point of research projects is not to regurgitate information that can already be found elsewhere. We have Google for that! What the student’s project should aim to do is promote an original idea or a spin on an existing idea, and use reliable sources to promote that idea. Copying or directly referencing a source without proper citation can lead to not only a poor grade, but accusations of academic dishonesty. By citing their sources regularly and accurately, students can easily avoid the trap of plagiarism , and promote further research on their topic.

They Create Better Researchers

By researching sources to back up and promote their ideas, students are becoming better researchers without even knowing it! Each time a new source is read or researched, the student is becoming more engaged with the project and is developing a deeper understanding of the subject area. Proper citations demonstrate a breadth of the student’s reading and dedication to the project itself. By creating citations, students are compelled to make connections between their sources and discern research patterns. Each time they complete this process, they are helping themselves become better researchers and writers overall.

When is the Right Time to Start Making Citations?

Make in-text/parenthetical citations as you need them.

As you are writing your paper, be sure to include references within the text that correspond with references in a works cited or bibliography. These are usually called in-text citations or parenthetical citations in MLA and APA formats. The most effective time to complete these is directly after you have made your reference to another source. For instance, after writing the line from Charles Dickens’ A Tale of Two Cities : “It was the best of times, it was the worst of times…,” you would include a citation like this (depending on your chosen citation style):

(Dickens 11).

This signals to the reader that you have referenced an outside source. What’s great about this system is that the in-text citations serve as a natural list for all of the citations you have made in your paper, which will make completing the works cited page a whole lot easier. After you are done writing, all that will be left for you to do is scan your paper for these references, and then build a works cited page that includes a citation for each one.

Need help creating an MLA works cited page ? Try the MLA format generator on EasyBib.com! We also have a guide on how to format an APA reference page .

2. Understand the General Formatting Rules of Your Citation Style Before You Start Writing

While reading up on paper formatting may not sound exciting, being aware of how your paper should look early on in the paper writing process is super important. Citation styles can dictate more than just the appearance of the citations themselves, but rather can impact the layout of your paper as a whole, with specific guidelines concerning margin width, title treatment, and even font size and spacing. Knowing how to organize your paper before you start writing will ensure that you do not receive a low grade for something as trivial as forgetting a hanging indent.

Don’t know where to start? Here’s a formatting guide on APA format .

3. Double-check All of Your Outside Sources for Relevance and Trustworthiness First

Collecting outside sources that support your research and specific topic is a critical step in writing an effective paper. But before you run to the library and grab the first 20 books you can lay your hands on, keep in mind that selecting a source to include in your paper should not be taken lightly. Before you proceed with using it to backup your ideas, run a quick Internet search for it and see if other scholars in your field have written about it as well. Check to see if there are book reviews about it or peer accolades. If you spot something that seems off to you, you may want to consider leaving it out of your work. Doing this before your start making citations can save you a ton of time in the long run.

Finished with your paper? It may be time to run it through a grammar and plagiarism checker , like the one offered by EasyBib Plus. If you’re just looking to brush up on the basics, our grammar guides  are ready anytime you are.

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Home » How to Cite Research Paper – All Formats and Examples

How to Cite Research Paper – All Formats and Examples

Table of Contents

Research Paper Citation

Research paper citation refers to the act of acknowledging and referencing a previously published work in a scholarly or academic paper . When citing sources, researchers provide information that allows readers to locate the original source, validate the claims or arguments made in the paper, and give credit to the original author(s) for their work.

The citation may include the author’s name, title of the publication, year of publication, publisher, and other relevant details that allow readers to trace the source of the information. Proper citation is a crucial component of academic writing, as it helps to ensure accuracy, credibility, and transparency in research.

How to Cite Research Paper

There are several formats that are used to cite a research paper. Follow the guide for the Citation of a Research Paper:

Last Name, First Name. Title of Book. Publisher, Year of Publication.

Example : Smith, John. The History of the World. Penguin Press, 2010.

Journal Article

Last Name, First Name. “Title of Article.” Title of Journal, vol. Volume Number, no. Issue Number, Year of Publication, pp. Page Numbers.

Example : Johnson, Emma. “The Effects of Climate Change on Agriculture.” Environmental Science Journal, vol. 10, no. 2, 2019, pp. 45-59.

Research Paper

Last Name, First Name. “Title of Paper.” Conference Name, Location, Date of Conference.

Example : Garcia, Maria. “The Importance of Early Childhood Education.” International Conference on Education, Paris, 5-7 June 2018.

Author’s Last Name, First Name. “Title of Webpage.” Website Title, Publisher, Date of Publication, URL.

Example : Smith, John. “The Benefits of Exercise.” Healthline, Healthline Media, 1 March 2022, https://www.healthline.com/health/benefits-of-exercise.

News Article

Last Name, First Name. “Title of Article.” Name of Newspaper, Date of Publication, URL.

Example : Robinson, Sarah. “Biden Announces New Climate Change Policies.” The New York Times, 22 Jan. 2021, https://www.nytimes.com/2021/01/22/climate/biden-climate-change-policies.html.

Author, A. A. (Year of publication). Title of book. Publisher.

Example: Smith, J. (2010). The History of the World. Penguin Press.

Author, A. A., Author, B. B., & Author, C. C. (Year of publication). Title of article. Title of Journal, volume number(issue number), page range.

Example: Johnson, E., Smith, K., & Lee, M. (2019). The Effects of Climate Change on Agriculture. Environmental Science Journal, 10(2), 45-59.

Author, A. A. (Year of publication). Title of paper. In Editor First Initial. Last Name (Ed.), Title of Conference Proceedings (page numbers). Publisher.

Example: Garcia, M. (2018). The Importance of Early Childhood Education. In J. Smith (Ed.), Proceedings from the International Conference on Education (pp. 60-75). Springer.

Author, A. A. (Year, Month Day of publication). Title of webpage. Website name. URL

Example: Smith, J. (2022, March 1). The Benefits of Exercise. Healthline. https://www.healthline.com/health/benefits-of-exercise

Author, A. A. (Year, Month Day of publication). Title of article. Newspaper name. URL.

Example: Robinson, S. (2021, January 22). Biden Announces New Climate Change Policies. The New York Times. https://www.nytimes.com/2021/01/22/climate/biden-climate-change-policies.html

Chicago/Turabian style

Please note that there are two main variations of the Chicago style: the author-date system and the notes and bibliography system. I will provide examples for both systems below.

Author-Date system:

• In-text citation: (Author Last Name Year, Page Number)
• Reference list: Author Last Name, First Name. Year. Title of Book. Place of publication: Publisher.
• In-text citation: (Smith 2005, 28)
• Reference list: Smith, John. 2005. The History of America. New York: Penguin Press.

Notes and Bibliography system:

• Footnote/Endnote citation: Author First Name Last Name, Title of Book (Place of publication: Publisher, Year), Page Number.
• Bibliography citation: Author Last Name, First Name. Title of Book. Place of publication: Publisher, Year.
• Footnote/Endnote citation: John Smith, The History of America (New York: Penguin Press, 2005), 28.
• Bibliography citation: Smith, John. The History of America. New York: Penguin Press, 2005.

JOURNAL ARTICLES:

• Reference list: Author Last Name, First Name. Year. “Article Title.” Journal Title Volume Number (Issue Number): Page Range.
• In-text citation: (Johnson 2010, 45)
• Reference list: Johnson, Mary. 2010. “The Impact of Social Media on Society.” Journal of Communication 60(2): 39-56.
• Footnote/Endnote citation: Author First Name Last Name, “Article Title,” Journal Title Volume Number, Issue Number (Year): Page Range.
• Bibliography citation: Author Last Name, First Name. “Article Title.” Journal Title Volume Number, Issue Number (Year): Page Range.
• Footnote/Endnote citation: Mary Johnson, “The Impact of Social Media on Society,” Journal of Communication 60, no. 2 (2010): 39-56.
• Bibliography citation: Johnson, Mary. “The Impact of Social Media on Society.” Journal of Communication 60, no. 2 (2010): 39-56.

RESEARCH PAPERS:

• Reference list: Author Last Name, First Name. Year. “Title of Paper.” Conference Proceedings Title, Location, Date. Publisher, Page Range.
• In-text citation: (Jones 2015, 12)
• Reference list: Jones, David. 2015. “The Effects of Climate Change on Agriculture.” Proceedings of the International Conference on Climate Change, Paris, France, June 1-3, 2015. Springer, 10-20.
• Footnote/Endnote citation: Author First Name Last Name, “Title of Paper,” Conference Proceedings Title, Location, Date (Place of publication: Publisher, Year), Page Range.
• Bibliography citation: Author Last Name, First Name. “Title of Paper.” Conference Proceedings Title, Location, Date. Place of publication: Publisher, Year.
• Footnote/Endnote citation: David Jones, “The Effects of Climate Change on Agriculture,” Proceedings of the International Conference on Climate Change, Paris, France, June 1-3, 2015 (New York: Springer, 10-20).
• Bibliography citation: Jones, David. “The Effects of Climate Change on Agriculture.” Proceedings of the International Conference on Climate Change, Paris, France, June 1-3, 2015. New York: Springer, 10-20.
• In-text citation: (Author Last Name Year)
• Reference list: Author Last Name, First Name. Year. “Title of Webpage.” Website Name. URL.
• In-text citation: (Smith 2018)
• Reference list: Smith, John. 2018. “The Importance of Recycling.” Environmental News Network. https://www.enn.com/articles/54374-the-importance-of-recycling.
• Footnote/Endnote citation: Author First Name Last Name, “Title of Webpage,” Website Name, URL (accessed Date).
• Bibliography citation: Author Last Name, First Name. “Title of Webpage.” Website Name. URL (accessed Date).
• Footnote/Endnote citation: John Smith, “The Importance of Recycling,” Environmental News Network, https://www.enn.com/articles/54374-the-importance-of-recycling (accessed April 8, 2023).
• Bibliography citation: Smith, John. “The Importance of Recycling.” Environmental News Network. https://www.enn.com/articles/54374-the-importance-of-recycling (accessed April 8, 2023).

NEWS ARTICLES:

• Reference list: Author Last Name, First Name. Year. “Title of Article.” Name of Newspaper, Month Day.
• In-text citation: (Johnson 2022)
• Reference list: Johnson, Mary. 2022. “New Study Finds Link Between Coffee and Longevity.” The New York Times, January 15.
• Footnote/Endnote citation: Author First Name Last Name, “Title of Article,” Name of Newspaper (City), Month Day, Year.
• Bibliography citation: Author Last Name, First Name. “Title of Article.” Name of Newspaper (City), Month Day, Year.
• Footnote/Endnote citation: Mary Johnson, “New Study Finds Link Between Coffee and Longevity,” The New York Times (New York), January 15, 2022.
• Bibliography citation: Johnson, Mary. “New Study Finds Link Between Coffee and Longevity.” The New York Times (New York), January 15, 2022.

Harvard referencing style

Format: Author’s Last name, First initial. (Year of publication). Title of book. Publisher.

Example: Smith, J. (2008). The Art of War. Random House.

Journal article:

Format: Author’s Last name, First initial. (Year of publication). Title of article. Title of journal, volume number(issue number), page range.

Example: Brown, M. (2012). The impact of social media on business communication. Harvard Business Review, 90(12), 85-92.

Research paper:

Format: Author’s Last name, First initial. (Year of publication). Title of paper. In Editor’s First initial. Last name (Ed.), Title of book (page range). Publisher.

Example: Johnson, R. (2015). The effects of climate change on agriculture. In S. Lee (Ed.), Climate Change and Sustainable Development (pp. 45-62). Springer.

Format: Author’s Last name, First initial. (Year, Month Day of publication). Title of page. Website name. URL.

Example: Smith, J. (2017, May 23). The history of the internet. Encyclopedia Britannica. https://www.britannica.com/topic/history-of-the-internet

News article:

Format: Author’s Last name, First initial. (Year, Month Day of publication). Title of article. Title of newspaper, page number (if applicable).

Example: Thompson, E. (2022, January 5). New study finds coffee may lower risk of dementia. The New York Times, A1.

IEEE Format

Author(s). (Year of Publication). Title of Book. Publisher.

Smith, J. K. (2015). The Power of Habit: Why We Do What We Do in Life and Business. Random House.

Journal Article:

Author(s). (Year of Publication). Title of Article. Title of Journal, Volume Number (Issue Number), page numbers.

Johnson, T. J., & Kaye, B. K. (2016). Interactivity and the Future of Journalism. Journalism Studies, 17(2), 228-246.

Author(s). (Year of Publication). Title of Paper. Paper presented at Conference Name, Location.

Jones, L. K., & Brown, M. A. (2018). The Role of Social Media in Political Campaigns. Paper presented at the 2018 International Conference on Social Media and Society, Copenhagen, Denmark.

• Website: Author(s) or Organization Name. (Year of Publication or Last Update). Title of Webpage. Website Name. URL.

Example: National Aeronautics and Space Administration. (2019, August 29). NASA’s Mission to Mars. NASA. https://www.nasa.gov/topics/journeytomars/index.html

• News Article: Author(s). (Year of Publication). Title of Article. Name of News Source. URL.

Example: Johnson, M. (2022, February 16). Climate Change: Is it Too Late to Save the Planet? CNN. https://www.cnn.com/2022/02/16/world/climate-change-planet-scn/index.html

Vancouver Style

In-text citation: Use superscript numbers to cite sources in the text, e.g., “The study conducted by Smith and Johnson^1 found that…”.

Reference list citation: Format: Author(s). Title of book. Edition if any. Place of publication: Publisher; Year of publication.

Example: Smith J, Johnson L. Introduction to Molecular Biology. 2nd ed. New York: Wiley-Blackwell; 2015.

In-text citation: Use superscript numbers to cite sources in the text, e.g., “Several studies have reported that^1,2,3…”.

Reference list citation: Format: Author(s). Title of article. Abbreviated name of journal. Year of publication; Volume number (Issue number): Page range.

Example: Jones S, Patel K, Smith J. The effects of exercise on cardiovascular health. J Cardiol. 2018; 25(2): 78-84.

In-text citation: Use superscript numbers to cite sources in the text, e.g., “Previous research has shown that^1,2,3…”.

Reference list citation: Format: Author(s). Title of paper. In: Editor(s). Title of the conference proceedings. Place of publication: Publisher; Year of publication. Page range.

Example: Johnson L, Smith J. The role of stem cells in tissue regeneration. In: Patel S, ed. Proceedings of the 5th International Conference on Regenerative Medicine. London: Academic Press; 2016. p. 68-73.

In-text citation: Use superscript numbers to cite sources in the text, e.g., “According to the World Health Organization^1…”.

Reference list citation: Format: Author(s). Title of webpage. Name of website. URL [Accessed Date].

Example: World Health Organization. Coronavirus disease (COVID-19) advice for the public. World Health Organization. https://www.who.int/emergencies/disease/novel-coronavirus-2019/advice-for-public [Accessed 3 March 2023].

In-text citation: Use superscript numbers to cite sources in the text, e.g., “According to the New York Times^1…”.

Reference list citation: Format: Author(s). Title of article. Name of newspaper. Year Month Day; Section (if any): Page number.

Example: Jones S. Study shows that sleep is essential for good health. The New York Times. 2022 Jan 12; Health: A8.

Author(s). Title of Book. Edition Number (if it is not the first edition). Publisher: Place of publication, Year of publication.

Example: Smith, J. Chemistry of Natural Products. 3rd ed.; CRC Press: Boca Raton, FL, 2015.

Journal articles:

Author(s). Article Title. Journal Name Year, Volume, Inclusive Pagination.

Example: Garcia, A. M.; Jones, B. A.; Smith, J. R. Selective Synthesis of Alkenes from Alkynes via Catalytic Hydrogenation. J. Am. Chem. Soc. 2019, 141, 10754-10759.

Research papers:

Author(s). Title of Paper. Journal Name Year, Volume, Inclusive Pagination.

Example: Brown, H. D.; Jackson, C. D.; Patel, S. D. A New Approach to Photovoltaic Solar Cells. J. Mater. Chem. 2018, 26, 134-142.

Author(s) (if available). Title of Webpage. Name of Website. URL (accessed Month Day, Year).

Example: National Institutes of Health. Heart Disease and Stroke. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/health-topics/heart-disease-and-stroke (accessed April 7, 2023).

News articles:

Author(s). Title of Article. Name of News Publication. Date of Publication. URL (accessed Month Day, Year).

Example: Friedman, T. L. The World is Flat. New York Times. April 7, 2023. https://www.nytimes.com/2023/04/07/opinion/world-flat-globalization.html (accessed April 7, 2023).

In AMA Style Format, the citation for a book should include the following information, in this order:

• Title of book (in italics)
• Edition (if applicable)
• Place of publication
• Year of publication

Lodish H, Berk A, Zipursky SL, et al. Molecular Cell Biology. 4th ed. New York, NY: W. H. Freeman; 2000.

In AMA Style Format, the citation for a journal article should include the following information, in this order:

• Title of article
• Abbreviated title of journal (in italics)
• Year of publication; volume number(issue number):page numbers.

Chen H, Huang Y, Li Y, et al. Effects of mindfulness-based stress reduction on depression in adolescents and young adults: a systematic review and meta-analysis. JAMA Netw Open. 2020;3(6):e207081. doi:10.1001/jamanetworkopen.2020.7081

In AMA Style Format, the citation for a research paper should include the following information, in this order:

• Title of paper
• Name of journal or conference proceeding (in italics)
• Volume number(issue number):page numbers.

Bredenoord AL, Kroes HY, Cuppen E, Parker M, van Delden JJ. Disclosure of individual genetic data to research participants: the debate reconsidered. Trends Genet. 2011;27(2):41-47. doi:10.1016/j.tig.2010.11.004

In AMA Style Format, the citation for a website should include the following information, in this order:

• Title of web page or article
• Name of website (in italics)
• Date of publication or last update (if available)
• URL (website address)
• Date of access (month day, year)

Centers for Disease Control and Prevention. How to protect yourself and others. CDC. Published February 11, 2022. Accessed February 14, 2022. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html

In AMA Style Format, the citation for a news article should include the following information, in this order:

• Name of newspaper or news website (in italics)
• Date of publication

Gorman J. Scientists use stem cells from frogs to build first living robots. The New York Times. January 13, 2020. Accessed January 14, 2020. https://www.nytimes.com/2020/01/13/science/living-robots-xenobots.html

Bluebook Format

One author: Daniel J. Solove, The Future of Reputation: Gossip, Rumor, and Privacy on the Internet (Yale University Press 2007).

Two or more authors: Martha Nussbaum and Saul Levmore, eds., The Offensive Internet: Speech, Privacy, and Reputation (Harvard University Press 2010).

Journal article

One author: Daniel J. Solove, “A Taxonomy of Privacy,” University of Pennsylvania Law Review 154, no. 3 (January 2006): 477-560.

Two or more authors: Ethan Katsh and Andrea Schneider, “The Emergence of Online Dispute Resolution,” Journal of Dispute Resolution 2003, no. 1 (2003): 7-19.

One author: Daniel J. Solove, “A Taxonomy of Privacy,” GWU Law School Public Law Research Paper No. 113, 2005.

Two or more authors: Ethan Katsh and Andrea Schneider, “The Emergence of Online Dispute Resolution,” Cyberlaw Research Paper Series Paper No. 00-5, 2000.

WebsiteElectronic Frontier Foundation, “Surveillance Self-Defense,” accessed April 8, 2023, https://ssd.eff.org/.

News article

One author: Mark Sherman, “Court Deals Major Blow to Net Neutrality Rules,” ABC News, January 14, 2014, https://abcnews.go.com/Politics/wireStory/court-deals-major-blow-net-neutrality-rules-21586820.

Two or more authors: Siobhan Hughes and Brent Kendall, “AT&T Wins Approval to Buy Time Warner,” Wall Street Journal, June 12, 2018, https://www.wsj.com/articles/at-t-wins-approval-to-buy-time-warner-1528847249.

In-Text Citation: (Author’s last name Year of Publication: Page Number)

Example: (Smith 2010: 35)

Reference List Citation: Author’s last name First Initial. Title of Book. Edition. Place of publication: Publisher; Year of publication.

Example: Smith J. Biology: A Textbook. 2nd ed. New York: Oxford University Press; 2010.

Example: (Johnson 2014: 27)

Reference List Citation: Author’s last name First Initial. Title of Article. Abbreviated Title of Journal. Year of publication;Volume(Issue):Page Numbers.

Example: Johnson S. The role of dopamine in addiction. J Neurosci. 2014;34(8): 2262-2272.

Example: (Brown 2018: 10)

Reference List Citation: Author’s last name First Initial. Title of Paper. Paper presented at: Name of Conference; Date of Conference; Place of Conference.

Example: Brown R. The impact of social media on mental health. Paper presented at: Annual Meeting of the American Psychological Association; August 2018; San Francisco, CA.

Example: (World Health Organization 2020: para. 2)

Reference List Citation: Author’s last name First Initial. Title of Webpage. Name of Website. URL. Published date. Accessed date.

Example: World Health Organization. Coronavirus disease (COVID-19) pandemic. WHO website. https://www.who.int/emergencies/disease-coronavirus-2019. Updated August 17, 2020. Accessed September 5, 2021.

Example: (Smith 2019: para. 5)

Reference List Citation: Author’s last name First Initial. Title of Article. Title of Newspaper or Magazine. Year of publication; Month Day:Page Numbers.

Example: Smith K. New study finds link between exercise and mental health. The New York Times. 2019;May 20: A6.

Purpose of Research Paper Citation

The purpose of citing sources in a research paper is to give credit to the original authors and acknowledge their contribution to your work. By citing sources, you are also demonstrating the validity and reliability of your research by showing that you have consulted credible and authoritative sources. Citations help readers to locate the original sources that you have referenced and to verify the accuracy and credibility of your research. Additionally, citing sources is important for avoiding plagiarism, which is the act of presenting someone else’s work as your own. Proper citation also shows that you have conducted a thorough literature review and have used the existing research to inform your own work. Overall, citing sources is an essential aspect of academic writing and is necessary for building credibility, demonstrating research skills, and avoiding plagiarism.

Advantages of Research Paper Citation

There are several advantages of research paper citation, including:

• Giving credit: By citing the works of other researchers in your field, you are acknowledging their contribution and giving credit where it is due.
• Strengthening your argument: Citing relevant and reliable sources in your research paper can strengthen your argument and increase its credibility. It shows that you have done your due diligence and considered various perspectives before drawing your conclusions.
• Demonstrating familiarity with the literature : By citing various sources, you are demonstrating your familiarity with the existing literature in your field. This is important as it shows that you are well-informed about the topic and have done a thorough review of the available research.
• Providing a roadmap for further research: By citing relevant sources, you are providing a roadmap for further research on the topic. This can be helpful for future researchers who are interested in exploring the same or related issues.
• Building your own reputation: By citing the works of established researchers in your field, you can build your own reputation as a knowledgeable and informed scholar. This can be particularly helpful if you are early in your career and looking to establish yourself as an expert in your field.

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Researcher, Academic Writer, Web developer

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A Quick Guide to Harvard Referencing | Citation Examples

Published on 14 February 2020 by Jack Caulfield . Revised on 15 September 2023.

Referencing is an important part of academic writing. It tells your readers what sources you’ve used and how to find them.

Harvard is the most common referencing style used in UK universities. In Harvard style, the author and year are cited in-text, and full details of the source are given in a reference list .

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Table of contents

Harvard in-text citation, creating a harvard reference list, harvard referencing examples, referencing sources with no author or date, frequently asked questions about harvard referencing.

A Harvard in-text citation appears in brackets beside any quotation or paraphrase of a source. It gives the last name of the author(s) and the year of publication, as well as a page number or range locating the passage referenced, if applicable:

Note that ‘p.’ is used for a single page, ‘pp.’ for multiple pages (e.g. ‘pp. 1–5’).

An in-text citation usually appears immediately after the quotation or paraphrase in question. It may also appear at the end of the relevant sentence, as long as it’s clear what it refers to.

When your sentence already mentions the name of the author, it should not be repeated in the citation:

Sources with multiple authors

When you cite a source with up to three authors, cite all authors’ names. For four or more authors, list only the first name, followed by ‘ et al. ’:

Sources with no page numbers

Some sources, such as websites , often don’t have page numbers. If the source is a short text, you can simply leave out the page number. With longer sources, you can use an alternate locator such as a subheading or paragraph number if you need to specify where to find the quote:

Multiple citations at the same point

When you need multiple citations to appear at the same point in your text – for example, when you refer to several sources with one phrase – you can present them in the same set of brackets, separated by semicolons. List them in order of publication date:

Multiple sources with the same author and date

If you cite multiple sources by the same author which were published in the same year, it’s important to distinguish between them in your citations. To do this, insert an ‘a’ after the year in the first one you reference, a ‘b’ in the second, and so on:

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A bibliography or reference list appears at the end of your text. It lists all your sources in alphabetical order by the author’s last name, giving complete information so that the reader can look them up if necessary.

The reference entry starts with the author’s last name followed by initial(s). Only the first word of the title is capitalised (as well as any proper nouns).

Sources with multiple authors in the reference list

As with in-text citations, up to three authors should be listed; when there are four or more, list only the first author followed by ‘ et al. ’:

Reference list entries vary according to source type, since different information is relevant for different sources. Formats and examples for the most commonly used source types are given below.

• Entire book
• Book chapter
• Translated book
• Edition of a book

Journal articles

• Print journal
• Online-only journal with DOI
• Online-only journal with no DOI
• General web page
• Online article or blog
• Social media post

Sometimes you won’t have all the information you need for a reference. This section covers what to do when a source lacks a publication date or named author.

No publication date

When a source doesn’t have a clear publication date – for example, a constantly updated reference source like Wikipedia or an obscure historical document which can’t be accurately dated – you can replace it with the words ‘no date’:

Note that when you do this with an online source, you should still include an access date, as in the example.

When a source lacks a clearly identified author, there’s often an appropriate corporate source – the organisation responsible for the source – whom you can credit as author instead, as in the Google and Wikipedia examples above.

When that’s not the case, you can just replace it with the title of the source in both the in-text citation and the reference list:

Prevent plagiarism, run a free check.

Harvard referencing uses an author–date system. Sources are cited by the author’s last name and the publication year in brackets. Each Harvard in-text citation corresponds to an entry in the alphabetised reference list at the end of the paper.

Vancouver referencing uses a numerical system. Sources are cited by a number in parentheses or superscript. Each number corresponds to a full reference at the end of the paper.

A Harvard in-text citation should appear in brackets every time you quote, paraphrase, or refer to information from a source.

The citation can appear immediately after the quotation or paraphrase, or at the end of the sentence. If you’re quoting, place the citation outside of the quotation marks but before any other punctuation like a comma or full stop.

In Harvard referencing, up to three author names are included in an in-text citation or reference list entry. When there are four or more authors, include only the first, followed by ‘ et al. ’

Though the terms are sometimes used interchangeably, there is a difference in meaning:

• A reference list only includes sources cited in the text – every entry corresponds to an in-text citation .
• A bibliography also includes other sources which were consulted during the research but not cited.

Cite this Scribbr article

If you want to cite this source, you can copy and paste the citation or click the ‘Cite this Scribbr article’ button to automatically add the citation to our free Reference Generator.

Caulfield, J. (2023, September 15). A Quick Guide to Harvard Referencing | Citation Examples. Scribbr. Retrieved 6 May 2024, from https://www.scribbr.co.uk/referencing/harvard-style/

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How to Cite a Research Paper in APA

Last Updated: October 19, 2022 Fact Checked

This article was co-authored by wikiHow Staff . Our trained team of editors and researchers validate articles for accuracy and comprehensiveness. wikiHow's Content Management Team carefully monitors the work from our editorial staff to ensure that each article is backed by trusted research and meets our high quality standards. There are 12 references cited in this article, which can be found at the bottom of the page. This article has been fact-checked, ensuring the accuracy of any cited facts and confirming the authority of its sources. This article has been viewed 159,844 times. Learn more...

If you’re citing a research article or paper in APA style, you’ll need to use a specific citation format that varies depending on the source. Assess whether your source is an article or report published in an academic journal or book, or whether it is an unpublished research paper, such as a print-only thesis or dissertation. Either way, your in-text citations will need to include information about the author (if available) and the date when your source was published or written.

Sample Citations

Writing an In-Text Citation

• For example, you may write, “Gardener (2008) notes, ‘There are several factors to consider about lobsters’ (p. 199).”

• For example, you may write, “‘There are several factors to consider about lobsters’ (Gardner, 2008, p. 199).” Or, “The paper claims, ‘The fallen angel trope is common in religious and non-religious texts’ (Meek & Hill, 2015, p.13-14).”
• For articles with 3-5 authors, write out the names of all the authors the first time you cite the source. For example: (Hammett, Wooster, Smith, & Charles, 1928). In subsequent citations, write only the first author’s name, followed by et al.: (Hammett et al., 1928).
• If there are 6 or more authors for the paper, include the last name of the first author listed and then write "et al." to indicate that there are more than 5 authors.
• For example, you may write, "'This is a quote' (Minaj et al., 1997, p. 45)."

• For example, you may write, “‘The risk of cervical cancer in women is rising’ (American Cancer Society, 2012, p. 2).”

• For example, you may write, “‘Shakespeare may have been a woman’ (“Radical English Literature,” 2004, p. 45).” Or, “The paper notes, ‘There is a boom in Virgin Mary imagery’ (“Art History in Italy,” 2011, p. 32).”

• For example, you may write, “‘There are several factors to consider about lobsters’ (Gardner, 2008, p. 199).” Or, “The paper claims, ‘The fallen angel trope is common in religious and non-religious texts’ (“Iconography in Italian Frescos,” 2015, p.13-14).”

• For example, you may write, “‘There are several factors to consider about lobsters’ (Gardner, 2008, p. 199).” Or, “The paper claims, ‘The fallen angel trope is common in religious and non-religious texts’ (“Iconography in Italian Frescos,” 2015, p.145-146).”

• For example, you may write, “‘The effects of food deprivation are long-term’ (Mett, 2005, para. 18).”

Creating a Reference List Citation for a Published Source

• Material on websites is also considered “published,” even if it’s not peer-reviewed or associated with a formal publishing company.
• While academic dissertations or theses that are print-only are considered unpublished, these types of documents are considered published if they’re included in an online database (such as ProQuest) or incorporated into an institutional repository.

• For example, you may write, “Gardner, L. M.” Or, “Meek, P. Q., Kendrick, L. H., & Hill, R. W.”
• If there is no author, you can list the name of the organization that published the research paper. For example, you may write, “American Cancer Society” or “The Reading Room.”
• Formally published documents that don’t list an author or that have a corporate author are typically reports or white papers .

• For example, you may write, “Gardner, L. M. (2008).” Or, “American Cancer Society. (2015).”

• For example, you may write, “Gardner, L. M. (2008). Crustaceans: Research and data.” Or, “American Cancer Society. (2015). Cervical cancer rates in women ages 20-45.”

• For example, for a journal article, you may write, “Gardner, L. M. (2008). Crustaceans: Research and data. Modern Journal of Malacostracan Research, 25, 150-305.”
• For a book chapter, you could write: “Wooster, B. W. (1937). A comparative study of modern Dutch cow creamers. In T. E. Travers (Ed.), A Detailed History of Tea Serviceware (pp. 127-155). London: Wimble Press."

• For example, you may write, “Kotb, M. A., Kamal, A. M., Aldossary, N. M., & Bedewi, M. A. (2019). Effect of vitamin D replacement on depression in multiple sclerosis patients. Multiple Sclerosis and Related Disorders, 29, 111-117. Retrieved from PubMed, https://www.ncbi.nlm.nih.gov/pubmed/30708308.
• If you’re citing a paper or article that was published online but did not come from an academic journal or database, provide information about the author (if known), the date of publication (if available), and the website where you found the article. For example: “Hill, M. (n.d.). Egypt in the Ptolemaic Period. Retrieved from https://www.metmuseum.org/toah/hd/ptol/hd_ptol.htm”

Citing Unpublished Sources in Your Reference List

• Print-only dissertations or theses.
• Articles or book chapters that are in press or have been recently prepared or submitted for publication.
• Papers that have been rejected for publication or were never intended for publication (such as student research papers or unpublished conference papers).

• If the paper is currently being prepared for publication, include the author’s name, the year when the current draft was completed, and the title of the article in italics, followed by “Manuscript in preparation.” For example: Wooster, B. W. (1932). What the well-dressed man is wearing. Manuscript in preparation.
• If the paper has been submitted for publication, format the citation the same way as if it were in preparation, but instead follow the title with “Manuscript submitted for publication.” For example: Wooster, B. W. (1932). What the well-dressed man is wearing. Manuscript submitted for publication.
• If the paper has been accepted for publication but is not yet published, replace the date with “in press.” Do not italicize the paper title, but do include the title of the periodical or book in which it will be published and italicize that. For example: Wooster, B. W. (in press). What the well-dressed man is wearing. Milady’s Boudoir.

• If the paper was written for a conference but never published, your citation should look like this: Riker, W. T. (2019, March). Traditional methods for the preparation of spiny lobe-fish. Paper presented at the 325th Annual Intergalactic Culinary Conference, San Francisco, CA.
• For an unpublished paper written by a student for a class, include details about the institution where the paper was written. For example: Crusher, B. H. (2019). A typology of Cardassian skin diseases. Unpublished manuscript, Department of External Medicine, Starfleet Academy, San Francisco, CA.

• For example, you may write, “Pendlebottom, R. H. (2011). Iconography in Italian Frescos (Unpublished doctoral dissertation). New York University, New York, United States.”

Community Q&A

• If you want certain information to stand out in the research paper, then you can consider using a block quote. Thanks Helpful 0 Not Helpful 0

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• ↑ https://libraryguides.vu.edu.au/apa-referencing/7JournalArticles
• ↑ https://owl.purdue.edu/owl/research_and_citation/apa_style/apa_formatting_and_style_guide/in_text_citations_author_authors.html
• ↑ https://bowvalleycollege.libguides.com/c.php?g=714519&p=5093747
• ↑ https://guides.libraries.psu.edu/apaquickguide/intext
• ↑ https://owl.purdue.edu/owl/research_and_citation/apa_style/apa_formatting_and_style_guide/in_text_citations_the_basics.html
• ↑ https://libguides.southernct.edu/c.php?g=7125&p=34582#1951239
• ↑ https://owl.purdue.edu/owl/research_and_citation/apa_style/apa_formatting_and_style_guide/reference_list_electronic_sources.html
• ↑ https://owl.purdue.edu/owl/research_and_citation/apa_style/apa_formatting_and_style_guide/reference_list_articles_in_periodicals.html
• ↑ https://owl.purdue.edu/owl/research_and_citation/apa_style/apa_formatting_and_style_guide/reference_list_books.html
• ↑ https://morlingcollege.libguides.com/apareferencing/unpublished-or-informally-published-work
• ↑ https://owl.purdue.edu/owl/research_and_citation/apa_style/apa_formatting_and_style_guide/general_apa_faqs.html
• ↑ https://owl.purdue.edu/owl/research_and_citation/apa_style/apa_formatting_and_style_guide/reference_list_other_print_sources.html

About This Article

To cite a research paper in-text in APA, name the author in the text to introduce the quote and put the publication date for the text in parentheses. At the end of your quote, put the page number in parentheses. If you don’t mention the author in your prose, include them in the citation. Start the citation, which should come at the end of the quote, by listing the author’s last name, the year of publication, and the page number. Make sure to put all of this information in parentheses. If there’s no author, use the name of the organization that published the paper or the first few words from the title. To learn how to cite published and unpublished sources in your reference list, keep reading! Did this summary help you? Yes No

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• Evaluate, Write & Cite

• is the right thing to do  to give credit to those who had the idea
• shows that you have read and understand  what experts have had to say about your topic
• helps people find the sources  that you used in case they want to read more about the topic
• provides   evidence  for your arguments
• is professional and  standard practice   for students and scholars

What is a Citation?

A citation identifies for the reader the original source for an idea, information, or image that is referred to in a work.

• In the body of a paper, the  in-text citation  acknowledges the source of information used.
• At the end of a paper, the citations are compiled on a  References  or  Works Cited  list. A basic citation includes the author, title, and publication information of the source. 

From:  Lemieux  Library,  University  of Seattle 

Why Should You Cite?

Quoting Are you quoting two or more consecutive words from a source? Then the original source should be cited and the words or phrase placed in quotes. 

Paraphrasing If an idea or information comes from another source,  even if you put it in your own words , you still need to credit the source.  General vs. Unfamiliar Knowledge You do not need to cite material which is accepted common knowledge. If in doubt whether your information is common knowledge or not, cite it. Formats We usually think of books and articles. However, if you use material from web sites, films, music, graphs, tables, etc. you'll also need to cite these as well.

Plagiarism is presenting the words or ideas of someone else as your own without proper acknowledgment of the source. When you work on a research paper and use supporting material from works by others, it's okay to quote people and use their ideas, but you do need to correctly credit them. Even when you summarize or paraphrase information found in books, articles, or Web pages, you must acknowledge the original author.

Citation Style Help

Helpful links:

• MLA ,  Works Cited : A Quick Guide (a template of core elements)
• CSE  (Council of Science Editors)

For additional writing resources specific to styles listed here visit the  Purdue OWL Writing Lab

Citation and Bibliography Resources

• How to Write an Annotated Bibliography
• << Previous: Evaluate Your Info
• Next: Evaluate, Write & Cite >>

Creative Commons Attribution 3.0 License except where otherwise noted.

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The land on which we gather is the unceded territory of the Awaswas-speaking Uypi Tribe. The Amah Mutsun Tribal Band, comprised of the descendants of indigenous people taken to missions Santa Cruz and San Juan Bautista during Spanish colonization of the Central Coast, is today working hard to restore traditional stewardship practices on these lands and heal from historical trauma.

The land acknowledgement used at UC Santa Cruz was developed in partnership with the Amah Mutsun Tribal Band Chairman and the Amah Mutsun Relearning Program at the UCSC Arboretum .

How To Write a Research Paper

• 1. Understand the Assignment
• 2. Choose Topic & Write Thesis Statement
• 3. Create Concept Map & Keyword List
• 4. Research Your Topic
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• 6. Write the Paper
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Why are citations important?

Apa citations.

Good research projects combine data from a variety of sources and carefully document the sources of information and ideas. Research documentation usually appears in two parts: short in-text citations occurring within the actual paper and a longer, complete list of works at the end of the paper called a bibliography, reference list, or works cited page. 

Besides giving credit to the source of information or ideas, there are other great reasons to cite in your research project:

• Persuasiveness - Your writing will be more persuasive if you cite the research on which you based your own conclusions and arguments.
• Sharing - Citations make it possible for your professor and other readers to examine interesting sources that you found.
• Communication -  Correct citations helps you communicate effectively with potential peers within a discipline.
• Skills -  Correct citation demonstrates your research and documentation abilities to your professor.
• Avoid Plagiarism -  Correct citation use helps protect you from plagiarizing.

Note: a hyperlink or URL included in the text is not the same as a citation. Ex: "Higher gas prices are on the way (cnn.com/specialreport)." URLs in the text, while common on the internet, are not considered a correct form of scholarly citation.

• Purdue University OWL - Online Writing Lab (APA)
• APA Citations, 6th Edition -- Seminole State College
• APA Citations -- Valencia College
• << Previous: Plagiarism
• Next: Credits >>
• Last Updated: Oct 31, 2023 9:15 AM
• URL: https://libguides.seminolestate.edu/researchpaper

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13.1 Formatting a Research Paper

Learning objectives.

• Identify the major components of a research paper written using American Psychological Association (APA) style.
• Apply general APA style and formatting conventions in a research paper.

In this chapter, you will learn how to use APA style , the documentation and formatting style followed by the American Psychological Association, as well as MLA style , from the Modern Language Association. There are a few major formatting styles used in academic texts, including AMA, Chicago, and Turabian:

• AMA (American Medical Association) for medicine, health, and biological sciences
• APA (American Psychological Association) for education, psychology, and the social sciences
• Chicago—a common style used in everyday publications like magazines, newspapers, and books
• MLA (Modern Language Association) for English, literature, arts, and humanities
• Turabian—another common style designed for its universal application across all subjects and disciplines

While all the formatting and citation styles have their own use and applications, in this chapter we focus our attention on the two styles you are most likely to use in your academic studies: APA and MLA.

If you find that the rules of proper source documentation are difficult to keep straight, you are not alone. Writing a good research paper is, in and of itself, a major intellectual challenge. Having to follow detailed citation and formatting guidelines as well may seem like just one more task to add to an already-too-long list of requirements.

Following these guidelines, however, serves several important purposes. First, it signals to your readers that your paper should be taken seriously as a student’s contribution to a given academic or professional field; it is the literary equivalent of wearing a tailored suit to a job interview. Second, it shows that you respect other people’s work enough to give them proper credit for it. Finally, it helps your reader find additional materials if he or she wishes to learn more about your topic.

Furthermore, producing a letter-perfect APA-style paper need not be burdensome. Yes, it requires careful attention to detail. However, you can simplify the process if you keep these broad guidelines in mind:

• Work ahead whenever you can. Chapter 11 “Writing from Research: What Will I Learn?” includes tips for keeping track of your sources early in the research process, which will save time later on.
• Get it right the first time. Apply APA guidelines as you write, so you will not have much to correct during the editing stage. Again, putting in a little extra time early on can save time later.
• Use the resources available to you. In addition to the guidelines provided in this chapter, you may wish to consult the APA website at http://www.apa.org or the Purdue University Online Writing lab at http://owl.english.purdue.edu , which regularly updates its online style guidelines.

General Formatting Guidelines

This chapter provides detailed guidelines for using the citation and formatting conventions developed by the American Psychological Association, or APA. Writers in disciplines as diverse as astrophysics, biology, psychology, and education follow APA style. The major components of a paper written in APA style are listed in the following box.

These are the major components of an APA-style paper:

Body, which includes the following:

• Headings and, if necessary, subheadings to organize the content
• In-text citations of research sources
• References page

All these components must be saved in one document, not as separate documents.

The title page of your paper includes the following information:

• Title of the paper
• Author’s name
• Name of the institution with which the author is affiliated
• Header at the top of the page with the paper title (in capital letters) and the page number (If the title is lengthy, you may use a shortened form of it in the header.)

List the first three elements in the order given in the previous list, centered about one third of the way down from the top of the page. Use the headers and footers tool of your word-processing program to add the header, with the title text at the left and the page number in the upper-right corner. Your title page should look like the following example.

The next page of your paper provides an abstract , or brief summary of your findings. An abstract does not need to be provided in every paper, but an abstract should be used in papers that include a hypothesis. A good abstract is concise—about one hundred fifty to two hundred fifty words—and is written in an objective, impersonal style. Your writing voice will not be as apparent here as in the body of your paper. When writing the abstract, take a just-the-facts approach, and summarize your research question and your findings in a few sentences.

In Chapter 12 “Writing a Research Paper” , you read a paper written by a student named Jorge, who researched the effectiveness of low-carbohydrate diets. Read Jorge’s abstract. Note how it sums up the major ideas in his paper without going into excessive detail.

Write an abstract summarizing your paper. Briefly introduce the topic, state your findings, and sum up what conclusions you can draw from your research. Use the word count feature of your word-processing program to make sure your abstract does not exceed one hundred fifty words.

Depending on your field of study, you may sometimes write research papers that present extensive primary research, such as your own experiment or survey. In your abstract, summarize your research question and your findings, and briefly indicate how your study relates to prior research in the field.

Margins, Pagination, and Headings

APA style requirements also address specific formatting concerns, such as margins, pagination, and heading styles, within the body of the paper. Review the following APA guidelines.

Use these general guidelines to format the paper:

• Set the top, bottom, and side margins of your paper at 1 inch.
• Use double-spaced text throughout your paper.
• Use a standard font, such as Times New Roman or Arial, in a legible size (10- to 12-point).
• Use continuous pagination throughout the paper, including the title page and the references section. Page numbers appear flush right within your header.
• Section headings and subsection headings within the body of your paper use different types of formatting depending on the level of information you are presenting. Additional details from Jorge’s paper are provided.

Begin formatting the final draft of your paper according to APA guidelines. You may work with an existing document or set up a new document if you choose. Include the following:

• Your title page
• The abstract you created in Note 13.8 “Exercise 1”
• Correct headers and page numbers for your title page and abstract

APA style uses section headings to organize information, making it easy for the reader to follow the writer’s train of thought and to know immediately what major topics are covered. Depending on the length and complexity of the paper, its major sections may also be divided into subsections, sub-subsections, and so on. These smaller sections, in turn, use different heading styles to indicate different levels of information. In essence, you are using headings to create a hierarchy of information.

The following heading styles used in APA formatting are listed in order of greatest to least importance:

• Section headings use centered, boldface type. Headings use title case, with important words in the heading capitalized.
• Subsection headings use left-aligned, boldface type. Headings use title case.
• The third level uses left-aligned, indented, boldface type. Headings use a capital letter only for the first word, and they end in a period.
• The fourth level follows the same style used for the previous level, but the headings are boldfaced and italicized.
• The fifth level follows the same style used for the previous level, but the headings are italicized and not boldfaced.

Visually, the hierarchy of information is organized as indicated in Table 13.1 “Section Headings” .

Table 13.1 Section Headings

A college research paper may not use all the heading levels shown in Table 13.1 “Section Headings” , but you are likely to encounter them in academic journal articles that use APA style. For a brief paper, you may find that level 1 headings suffice. Longer or more complex papers may need level 2 headings or other lower-level headings to organize information clearly. Use your outline to craft your major section headings and determine whether any subtopics are substantial enough to require additional levels of headings.

Working with the document you developed in Note 13.11 “Exercise 2” , begin setting up the heading structure of the final draft of your research paper according to APA guidelines. Include your title and at least two to three major section headings, and follow the formatting guidelines provided above. If your major sections should be broken into subsections, add those headings as well. Use your outline to help you.

Because Jorge used only level 1 headings, his Exercise 3 would look like the following:

Citation Guidelines

In-text citations.

Throughout the body of your paper, include a citation whenever you quote or paraphrase material from your research sources. As you learned in Chapter 11 “Writing from Research: What Will I Learn?” , the purpose of citations is twofold: to give credit to others for their ideas and to allow your reader to follow up and learn more about the topic if desired. Your in-text citations provide basic information about your source; each source you cite will have a longer entry in the references section that provides more detailed information.

In-text citations must provide the name of the author or authors and the year the source was published. (When a given source does not list an individual author, you may provide the source title or the name of the organization that published the material instead.) When directly quoting a source, it is also required that you include the page number where the quote appears in your citation.

This information may be included within the sentence or in a parenthetical reference at the end of the sentence, as in these examples.

Epstein (2010) points out that “junk food cannot be considered addictive in the same way that we think of psychoactive drugs as addictive” (p. 137).

Here, the writer names the source author when introducing the quote and provides the publication date in parentheses after the author’s name. The page number appears in parentheses after the closing quotation marks and before the period that ends the sentence.

Addiction researchers caution that “junk food cannot be considered addictive in the same way that we think of psychoactive drugs as addictive” (Epstein, 2010, p. 137).

Here, the writer provides a parenthetical citation at the end of the sentence that includes the author’s name, the year of publication, and the page number separated by commas. Again, the parenthetical citation is placed after the closing quotation marks and before the period at the end of the sentence.

As noted in the book Junk Food, Junk Science (Epstein, 2010, p. 137), “junk food cannot be considered addictive in the same way that we think of psychoactive drugs as addictive.”

Here, the writer chose to mention the source title in the sentence (an optional piece of information to include) and followed the title with a parenthetical citation. Note that the parenthetical citation is placed before the comma that signals the end of the introductory phrase.

David Epstein’s book Junk Food, Junk Science (2010) pointed out that “junk food cannot be considered addictive in the same way that we think of psychoactive drugs as addictive” (p. 137).

Another variation is to introduce the author and the source title in your sentence and include the publication date and page number in parentheses within the sentence or at the end of the sentence. As long as you have included the essential information, you can choose the option that works best for that particular sentence and source.

Citing a book with a single author is usually a straightforward task. Of course, your research may require that you cite many other types of sources, such as books or articles with more than one author or sources with no individual author listed. You may also need to cite sources available in both print and online and nonprint sources, such as websites and personal interviews. Chapter 13 “APA and MLA Documentation and Formatting” , Section 13.2 “Citing and Referencing Techniques” and Section 13.3 “Creating a References Section” provide extensive guidelines for citing a variety of source types.

Writing at Work

APA is just one of several different styles with its own guidelines for documentation, formatting, and language usage. Depending on your field of interest, you may be exposed to additional styles, such as the following:

• MLA style. Determined by the Modern Languages Association and used for papers in literature, languages, and other disciplines in the humanities.
• Chicago style. Outlined in the Chicago Manual of Style and sometimes used for papers in the humanities and the sciences; many professional organizations use this style for publications as well.
• Associated Press (AP) style. Used by professional journalists.

References List

The brief citations included in the body of your paper correspond to the more detailed citations provided at the end of the paper in the references section. In-text citations provide basic information—the author’s name, the publication date, and the page number if necessary—while the references section provides more extensive bibliographical information. Again, this information allows your reader to follow up on the sources you cited and do additional reading about the topic if desired.

The specific format of entries in the list of references varies slightly for different source types, but the entries generally include the following information:

• The name(s) of the author(s) or institution that wrote the source
• The year of publication and, where applicable, the exact date of publication
• The full title of the source
• For books, the city of publication
• For articles or essays, the name of the periodical or book in which the article or essay appears
• For magazine and journal articles, the volume number, issue number, and pages where the article appears
• For sources on the web, the URL where the source is located

The references page is double spaced and lists entries in alphabetical order by the author’s last name. If an entry continues for more than one line, the second line and each subsequent line are indented five spaces. Review the following example. ( Chapter 13 “APA and MLA Documentation and Formatting” , Section 13.3 “Creating a References Section” provides extensive guidelines for formatting reference entries for different types of sources.)

In APA style, book and article titles are formatted in sentence case, not title case. Sentence case means that only the first word is capitalized, along with any proper nouns.

Key Takeaways

• Following proper citation and formatting guidelines helps writers ensure that their work will be taken seriously, give proper credit to other authors for their work, and provide valuable information to readers.
• Working ahead and taking care to cite sources correctly the first time are ways writers can save time during the editing stage of writing a research paper.
• APA papers usually include an abstract that concisely summarizes the paper.
• APA papers use a specific headings structure to provide a clear hierarchy of information.
• In APA papers, in-text citations usually include the name(s) of the author(s) and the year of publication.
• In-text citations correspond to entries in the references section, which provide detailed bibliographical information about a source.

Writing for Success Copyright © 2015 by University of Minnesota is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License , except where otherwise noted.

How To Do In-Text Citations with Multiple Authors in APA Format

APA (or American Psychological Association) Style   was introduced in 1929 to establish a consistent style guide for scientific writing. It sought to make scientific works easier to read and understand. However, the style guidelines have expanded to include many disciplines, such as the humanities and health care.

The APA’s Publication Manual does not cover the general writing style rules in other editorial style guides, such as the MLA Handbook . APA Style seeks to create uniformity of common writing styles relevant to behavior and social sciences primarily.

Consistent formatting allows the reader to engage with the presented ideas rather than be distracted by the author’s personal formatting preferences. It also helps readers quickly review the document for references and sources to aid their research. Using APA Style keeps authors transparent by providing rules about citing their sources and giving credit for others’ ideas.

How to do in-text citations in APA

• Understanding “et. al.” usage in APA

Citing multiple authors in APA

• In-text citations for various author types in APA

Best practices and common mistakes

APA Style allows writers to credit and cite other works appropriately and avoid plagiarism through in-text citations. APA Style uses the author–date citation system, which requires notations to be included within the document to reference ideas, paraphrases and quotations from other bodies of work. Each in-text citation within the paper (or chart, footnote or figure) briefly identifies the cited work and guides the reader to a longer list of cited sources at the end of the document, called the reference list.

In-text citations can be written within a paper parenthetically or narratively. Both include the same information: the author’s last name and the publication date.

• Parenthetical citation : Great falls can be caused by sitting on tall walls (Dumpty, 1797).
• Narrative citation : Dumpty (1797) claims that great falls can be caused by sitting on tall walls.
• Reference list entry: Dumpty, Humpty (1797). Humpty Dumpty Sat on a Wall. Nursery Rhymes, 100.

APA Style requires citations to conform to a set of guidelines , which includes proper spelling of author names, consistency between the in-text citation information and its reference list entry and rules about crediting all facts and figures mentioned – especially those which are not common knowledge.

Understanding “et al.” usage in APA

Et al. is an abbreviation used to indicate multiple people. It’s the abbreviated version of “et alia,” a neutral plural version of “and others.” Most commonly, et al. indicates more than one contributor, such as multiple authors or editors, in a work.

In APA Style citations, et al. is used to indicate a cited work with three or more authors and serves as a way to condense the in-text citation to avoid confusion and unnecessary length. An APA in-text citation with three or more authors will include only the first author’s name plus “et al.” in every citation.

Citing multiple authors in APA Style is similar to MLA Style . For one or two authors, list the last name(s) followed by the year of publication. 

• One author: (Beyonce, 1997)
• Contributors: Daryl Hall and John Oates

To cite three or more authors using APA Style, use only the first author’s last name listed, plus “et al.” 

• Contributors: Earth, Wind and Fire

When two separate sources have the same abbreviated et al. form , spell out as many last names as needed to distinguish the sources from each other. It may include two last names followed by et al.

Similarly, when the first authors of separate sources share the same last name but have different initials, use their first initials in the in-text citations.

• Beyonce Knowles & Solange Knowles

In-text citation for various author types in APA

You may face a challenging situation where you must cite a group author , such as an institution or university, rather than a list of authors’ names. In this instance, you’ll list the group or organization.

• Group author: (Furman University, 2020)

If the group also has an abbreviation to its name, you may note the first and subsequent citations differently to be as concise as possible.

• Group author with abbreviation – 1st citation: (American Psychological Association [APA], 2024)
• Group author with abbreviation – 2nd citation : (APA, 2024)

The most common mistake when citing sources is forgetting to cite a source. One way to ensure you include all required sources is to document and manage your sources as you use their ideas within the document. This may mean you create the citations as you conduct your research, create your outline or type the final paper.

Some applications exist to help you manage and document citations, including EasyBib , Mendeley , EndNote and Zotero . Depending on your writing style, these applications can help you create citations, save your research sources, annotate documents and format references. 

Regarding best practices for in-text citations in APA Style, it’s good practice to proofread your citations and reference list together. When citing multiple authors, ensure all spellings are accurate and consistent throughout the document and reference list. Refer to the APA Style Publication Manual and other guideline reference documents to confirm your citing within the latest citation guidelines.

Giving credit to other authors who have shaped your research and ideas is incredibly important. You can do so without risking plagiarism accusations through in-text citations that are marked and referenced. Not only does it provide you with an honest and accurate reputation, but it also helps your readers gain more valuable knowledge from other sources.

Citing sources should not discourage you from sharing your knowledge within academic writing. Sooner or later, you’ll become a pro at in-text citations in APA style! The more you write, the more familiar you’ll become with the guidelines; you’ll no longer need to reference the style guides for help.

The perspectives and thoughts shared in the Furman Blog belong solely to the author and may not align with the official stance or policies of Furman University. All referenced sources were accurate as of the date of publication.

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5 Things To Keep In Mind While Writing A College Paper

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Research before writing the research paper

Writing a research paper is not an easy task, and it makes students most of the time very stressed. Sometimes the future depends on the research paper, which is why writing it correctly is essential. Most of the time, different niches of paper have another format, but the point of view of writing is the same. Professors want students to write the paper in such a way that they quickly convey their research.

To help you more about writing a research paper, here are some points that should not be missed. These key points will help you in writing and make the process of registering easy.

Select A Good Topic:

The first thing that earns the brownie point is the topic selected for writing the research paper. If the topic is good, the professor instantly grabs attention and reads it correctly. Selecting a good topic is the crucial point of writing any research paper. While choosing the case, always choose a unique topic and will help in knowing the subject better.

A good topic selection shows that the student is clear about the research and keen to deliver their studies to society.

Research Well About The Topic:

After selecting the topic, the next thing to do is research well about the subject. Read all the information from different-different sources and do not summit from a single source. It is essential to know the topic well before you start writing it down. While researching, always check if the source is reliable and then grasp that information of the relevant subject.

When the research is done up to the mark, it becomes easy to write it on paper. As the topic is precise, you can easily convey your points and make professors communicate about your research.

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Include All The Necessary Details:

The third thing after completing the research is to write it down in the paper. Whatever you researched about the topic, try to include it in your research paper. While writing, always follows the format as it gives a direction to the research paper. Also, when a student follows the design, it makes professors comfortable in reading the article.

Even while referring different-different sources, it is essential to mention all the details in the paper. So that professors get to know the basis of your information.

Check For Errors:

The fourth thing to do is to check all the errors. If the research paper is filled with mistakes, it might get rejected. Also, after writing the essay, proofread it two times and check its error on different-different software. Edit all the grammatical mistakes and before submitting it, check and remove even the slightest syntax error.

An error-free research paper helps in scoring better marks as it gives professors a vision that students are clear about the topic and know what they want to convey about their observations.

Write Good Citations:

Citation plays a significant role in what you are going to convey in your research paper . Try to get your message directly and include all your opinion with facts. Whatever you are trying to say, convey it now without any twist and turn. Always try to make the flow and language easy to understand.

By following these steps, a student can write a good research paper. A well-written essay helps students know the subject better and helps in grabbing a good opportunity in the future. Always remember to research the topic well and cite it from a clean and clear point of view. After completing the paper, always check the errors and proofread them before the submissions. You can also check out our blog on how to write a research paper appendix .

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Volume 30, Number 7—July 2024

Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus Infection in Domestic Dairy Cattle and Cats, United States, 2024

Suggested citation for this article

We report highly pathogenic avian influenza A(H5N1) virus in dairy cattle and cats in Kansas and Texas, United States, which reflects the continued spread of clade 2.3.4.4b viruses that entered the country in late 2021. Infected cattle experienced nonspecific illness, reduced feed intake and rumination, and an abrupt drop in milk production, but fatal systemic influenza infection developed in domestic cats fed raw (unpasteurized) colostrum and milk from affected cows. Cow-to-cow transmission appears to have occurred because infections were observed in cattle on Michigan, Idaho, and Ohio farms where avian influenza virus–infected cows were transported. Although the US Food and Drug Administration has indicated the commercial milk supply remains safe, the detection of influenza virus in unpasteurized bovine milk is a concern because of potential cross-species transmission. Continued surveillance of highly pathogenic avian influenza viruses in domestic production animals is needed to prevent cross-species and mammal-to-mammal transmission.

Highly pathogenic avian influenza (HPAI) viruses pose a threat to wild birds and poultry globally, and HPAI H5N1 viruses are of even greater concern because of their frequent spillover into mammals. In late 2021, the Eurasian strain of H5N1 (clade 2.3.4.4b) was detected in North America ( 1 , 2 ) and initiated an outbreak that continued into 2024. Spillover detections and deaths from this clade have been reported in both terrestrial and marine mammals in the United States ( 3 , 4 ). The detection of HPAI H5N1 clade 2.3.4.4b virus in severe cases of human disease in Ecuador ( 5 ) and Chile ( 6 ) raises further concerns regarding the pandemic potential of specific HPAI viruses.

In February 2024, veterinarians were alerted to a syndrome occurring in lactating dairy cattle in the panhandle region of northern Texas. Nonspecific illness accompanied by reduced feed intake and rumination and an abrupt drop in milk production developed in affected animals. The milk from most affected cows had a thickened, creamy yellow appearance similar to colostrum. On affected farms, incidence appeared to peak 4–6 days after the first animals were affected and then tapered off within 10–14 days; afterward, most animals were slowly returned to regular milking. Clinical signs were commonly reported in multiparous cows during middle to late lactation; ≈10%–15% illness and minimal death of cattle were observed on affected farms. Initial submissions of blood, urine, feces, milk, and nasal swab samples and postmortem tissues to regional diagnostic laboratories did not reveal a consistent, specific cause for reduced milk production. Milk cultures were often negative, and serum chemistry testing showed mildly increased aspartate aminotransferase, gamma-glutamyl transferase, creatinine kinase, and bilirubin values, whereas complete blood counts showed variable anemia and leukocytopenia.

In early March 2024, similar clinical cases were reported in dairy cattle in southwestern Kansas and northeastern New Mexico; deaths of wild birds and domestic cats were also observed within affected sites in the Texas panhandle. In > 1 dairy farms in Texas, deaths occurred in domestic cats fed raw colostrum and milk from sick cows that were in the hospital parlor. Antemortem clinical signs in affected cats were depressed mental state, stiff body movements, ataxia, blindness, circling, and copious oculonasal discharge. Neurologic exams of affected cats revealed the absence of menace reflexes and pupillary light responses with a weak blink response.

On March 21, 2024, milk, serum, and fresh and fixed tissue samples from cattle located in affected dairies in Texas and 2 deceased cats from an affected Texas dairy farm were received at the Iowa State University Veterinary Diagnostic Laboratory (ISUVDL; Ames, IA, USA). The next day, similar sets of samples were received from cattle located in affected dairies in Kansas. Milk and tissue samples from cattle and tissue samples from the cats tested positive for influenza A virus (IAV) by screening PCR, which was confirmed and characterized as HPAI H5N1 virus by the US Department of Agriculture National Veterinary Services Laboratory. Detection led to an initial press release by the US Department of Agriculture Animal and Plant Health Inspection Service on March 25, 2024, confirming HPAI virus in dairy cattle ( 7 ). We report the characterizations performed at the ISUVDL for HPAI H5N1 viruses infecting cattle and cats in Kansas and Texas.

Materials and Methods

Milk samples (cases 2–5) and fresh and formalin-fixed tissues (cases 1, 3–5) from dairy cattle were received at the ISUVDL from Texas on March 21 and from Kansas on March 22, 2024. The cattle exhibited nonspecific illness and reduced lactation, as described previously. The tissue samples for diagnostic testing came from 3 cows that were euthanized and 3 that died naturally; all postmortem examinations were performed on the premises of affected farms.

The bodies of 2 adult domestic shorthaired cats from a north Texas dairy farm were received at the ISUVDL for a complete postmortem examination on March 21, 2024. The cats were found dead with no apparent signs of injury and were from a resident population of ≈24 domestic cats that had been fed milk from sick cows. Clinical disease in cows on that farm was first noted on March 16; the cats became sick on March 17, and several cats died in a cluster during March 19–20. In total, >50% of the cats at that dairy became ill and died. We collected cerebrum, cerebellum, eye, lung, heart, spleen, liver, lymph node, and kidney tissue samples from the cats and placed them in 10% neutral-buffered formalin for histopathology.

At ISUVDL, we trimmed, embedded in paraffin, and processed formalin-fixed tissues from affected cattle and cats for hematoxylin/eosin staining and histologic evaluation. For immunohistochemistry (IHC), we prepared 4-µm–thick sections from paraffin-embedded tissues, placed them on Superfrost Plus slides (VWR, https://www.vwr.com ), and dried them for 20 minutes at 60°C. We used a Ventana Discovery Ultra IHC/ISH research platform (Roche, https://www.roche.com ) for deparaffinization until and including counterstaining. We obtained all products except the primary antibody from Roche. Automated deparaffination was followed by enzymatic digestion with protease 1 for 8 minutes at 37°C and endogenous peroxidase blocking. We obtained the primary influenza A virus antibody from the hybridoma cell line H16-L10–4R5 (ATCC, https://www.atcc.org ) and diluted at 1:100 in Discovery PSS diluent; we incubated sections with antibody for 32 minutes at room temperature. Next, we incubated the sections with a hapten-labeled conjugate, Discovery anti-mouse HQ, for 16 minutes at 37°C followed by a 16-minute incubation with the horse radish peroxidase conjugate, Discovery anti-HQ HRP. We used a ChromoMap DAB kit for antigen visualization, followed by counterstaining with hematoxylin and then bluing. Positive controls were sections of IAV-positive swine lung. Negative controls were sections of brain, lung, and eyes from cats not infected with IAV.

We diluted milk samples 1:3 vol/vol in phosphate buffered saline, pH 7.4 (Gibco/Thermo Fisher Scientific, https://www.thermofisher.com ) by mixing 1 unit volume of milk and 3 unit volumes of phosphate buffered saline. We prepared 10% homogenates of mammary glands, brains, lungs, spleens, and lymph nodes in Earle’s balanced salt solution (Sigma-Aldrich, https://www.sigmaaldrich.com ). Processing was not necessary for ocular fluid, rumen content, or serum samples. After processing, we extracted samples according to a National Animal Health Laboratory Network (NAHLN) protocol that had 2 NAHLN-approved deviations for ISUVDL consisting of the MagMax Viral RNA Isolation Kit for 100 µL sample volumes and a Kingfisher Flex instrument (both Thermo Fisher Scientific).

We performed real-time reverse transcription PCR (rRT-PCR) by using an NAHLN-approved assay with 1 deviation, which was the VetMAX-Gold SIV Detection kit (Thermo Fisher Scientific), to screen for the presence of IAV RNA. We tested samples along with the VetMAX XENO Internal Positive Control to monitor the possible presence of PCR inhibitors. Each rRT-PCR 96-well plate had 2 positive amplification controls, 2 negative amplification controls, 1 positive extraction control, and 1 negative extraction control. We ran the rRT-PCR on an ABI 7500 Fast thermocycler and analyzed data with Design and Analysis Software 2.7.0 (both Thermo Fisher Scientific). We considered samples with cycle threshold (Ct) values <40.0 to be positive for virus.

After the screening rRT-PCR, we analyzed IAV RNA–positive samples for the H5 subtype and H5 clade 2.3.4.4b by using the same RNA extraction and NAHLN-approved rRT-PCR protocols as described previously, according to standard operating procedures. We performed PCR on the ABI 7500 Fast thermocycler by using appropriate controls to detect H5-specific IAV. We considered samples with Ct values <40.0 to be positive for the IAV H5 subtype.

We conducted genomic sequencing of 2 milk samples from infected dairy cattle from Texas and 2 tissue samples (lung and brain) from cats that died at a different Texas dairy. We subjected the whole-genome sequencing data to bioinformatics analysis to assemble the 8 different IAV segment sequences according to previously described methods ( 8 ). We used the hemagglutinin (HA) and neuraminidase (NA) sequences for phylogenetic analysis. We obtained reference sequences for the HA and NA segments of IAV H5 clade 2.3.4.4 from publicly available databases, including GISAID ( https://www.gisaid.org ) and GenBank. We aligned the sequences by using MAFFT version 7.520 software ( https://mafft.cbrc.jp/alignment/server/index.html ) to create multiple sequence alignments for subsequent phylogenetic analysis. We used IQTree2 ( https://github.com/iqtree/iqtree2 ) to construct the phylogenetic tree from the aligned sequences. The software was configured to automatically identify the optimal substitution model by using the ModelFinder Plus option, ensuring the selection of the most suitable model for the dataset and, thereby, improving the accuracy of the reconstructed tree. We visualized the resulting phylogenetic tree by using iTOL ( https://itol.embl.de ), a web-based platform for interactive tree exploration and annotation.

Gross Lesions in Cows and Cats

All cows were in good body condition with adequate rumen fill and no external indications of disease. Postmortem examinations of the affected dairy cows revealed firm mammary glands typical of mastitis; however, mammary gland lesions were not consistent. Two cows that were acutely ill before postmortem examination had grossly normal milk and no abnormal mammary gland lesions. The gastrointestinal tract of some cows had small abomasal ulcers and shallow linear erosions of the intestines, but those observations were also not consistent in all animals. The colon contents were brown and sticky, suggesting moderate dehydration. The feces contained feed particles that appeared to have undergone minimal ruminal fermentation. The rumen contents had normal color and appearance but appeared to have undergone minimal fermentation.

The 2 adult cats (1 intact male, 1 intact female) received at the ISUVDL were in adequate body and postmortem condition. External examination was unremarkable. Mild hemorrhages were observed in the subcutaneous tissues over the dorsal skull, and multifocal meningeal hemorrhages were observed in the cerebrums of both cats. The gastrointestinal tracts were empty, and no other gross lesions were observed.

Microscopic Lesions in Cows and Cats

Figure 1 . Mammary gland lesions in cattle in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024. A, B) Mammary gland...

The chief microscopic lesion observed in affected cows was moderate acute multifocal neutrophilic mastitis ( Figure 1 ); however, mammary glands were not received from every cow. Three cows had mild neutrophilic or lymphocytic hepatitis. Because they were adult cattle, other observed microscopic lesions (e.g., mild lymphoplasmacytic interstitial nephritis and mild to moderate lymphocytic abomasitis) were presumed to be nonspecific, age-related changes. We did not observe major lesions in the other evaluated tissues. We performed IHC for IAV antigen on all evaluated tissues; the only tissues with positive immunoreactivity were mastitic mammary glands from 2 cows that showed nuclear and cytoplasmic labeling of alveolar epithelial cells and cells within lumina ( Figure 1 ) and multifocal germinal centers within a lymph node from 1 cow ( Table 1 ).

Figure 2 . Lesions in cat tissues in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024. Tissue sections were stained with...

Both cats had microscopic lesions consistent with severe systemic virus infection, including severe subacute multifocal necrotizing and lymphocytic meningoencephalitis with vasculitis and neuronal necrosis, moderate subacute multifocal necrotizing and lymphocytic interstitial pneumonia, moderate to severe subacute multifocal necrotizing and lymphohistiocytic myocarditis, and moderate subacute multifocal lymphoplasmacytic chorioretinitis with ganglion cell necrosis and attenuation of the internal plexiform and nuclear layers ( Table 2 ; Figure 2 ). We performed IHC for IAV antigen on multiple tissues (brain, eye, lung, heart, spleen, liver, and kidney). We detected positive IAV immunoreactivity in brain (intracytoplasmic, intranuclear, and axonal immunolabeling of neurons), lung, and heart, and multifocal and segmental immunoreactivity within all layers of the retina ( Figure 2 ).

PCR Data from Cows and Cats

We tested various samples from 8 clinically affected mature dairy cows by IAV screening and H5 subtype-specific PCR ( Table 3 ). Milk and mammary gland homogenates consistently showed low Ct values: 12.3–16.9 by IAV screening PCR, 17.6–23.1 by H5 subtype PCR, and 14.7–20.0 by H5 2.3.4.4 clade PCR (case 1, cow 1; case 2, cows 1 and 2; case 3, cow 1; and case 4, cow 1). We forwarded the samples to the National Veterinary Services Laboratory, which confirmed the virus was an HPAI H5N1 virus strain.

When available, we also tested tissue homogenates (e.g., lung, spleen, and lymph nodes), ocular fluid, and rumen contents from 6 cows by IAV and H5 subtype-specific PCR ( Table 3 ). However, the PCR findings were not consistent. For example, the tissue homogenates and ocular fluid tested positive in some but not all cows. In case 5, cow 1, the milk sample tested negative by IAV screening PCR, but the spleen homogenate tested positive by IAV screening, H5 subtype, and H5 2.3.4.4 PCR. For 2 cows (case 3, cow 1; and case 4, cow 1) that had both milk and rumen contents available, both samples tested positive for IAV. Nevertheless, all IAV-positive nonmammary gland tissue homogenates, ocular fluid, and rumen contents had markedly elevated Ct values in contrast to the low Ct values for milk and mammary gland homogenate samples.

We tested brain and lung samples from the 2 cats (case 6, cats 1 and 2) by IAV screening and H5 subtype-specific PCR ( Table 3 ). Both sample types were positive by IAV screening PCR; Ct values were 9.9–13.5 for brain and 17.4–24.4 for lung samples, indicating high amounts of virus nucleic acid in those samples. The H5 subtype and H5 2.3.4.4 PCR results were also positive for the brain and lung samples; Ct values were consistent with the IAV screening PCR ( Table 3 ).

Phylogenetic Analyses

We assembled the sequences of all 8 segments of the HPAI viruses from both cow milk and cat tissue samples. We used the hemagglutinin (HA) and neuraminidase (NA) sequences specifically for phylogenetic analysis to delineate the clade of the HA gene and subtype of the NA gene.

Figure 3 . Phylogenetic analysis of hemagglutinin gene sequences in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024. Colors indicate different...

For HA gene analysis, both HA sequences derived from cow milk samples exhibited a high degree of similarity, sharing 99.88% nucleotide identity, whereas the 2 HA sequences from cat tissue samples showed complete identity at 100%. The HA sequences from the milk samples had 99.94% nucleotide identities with HA sequences from the cat tissues, resulting in a distinct subcluster comprising all 4 HA sequences, which clustered together with other H5N1 viruses belonging to clade 2.3.4.4b ( Figure 3 ). The HA sequences were deposited in GenBank (accession nos. PP599465 [case 2, cow 1], PP599473 [case 2, cow 2], PP692142 [case 6, cat 1], and PP692195 [case 6, cat 2]).

Figure 4 . Phylogenetic analysis of neuraminidase gene sequences in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024. Colors indicate different...

For NA gene analysis, the 2 NA sequences obtained from cow milk samples showed 99.93% nucleotide identity. Moreover, the NA sequences derived from the milk samples exhibited complete nucleotide identities (100%) with those from the cat tissues. The 4 NA sequences were grouped within the N1 subtype of HPAI viruses ( Figure 4 ). The NA sequences were deposited in GenBank (accession nos. PP599467 [case 2, cow 1], PP599475 [case 2, cow 2], PP692144 [case 6, cat 1], and PP692197 [case 6, cat 2]).

This case series differs from most previous reports of IAV infection in bovids, which indicated cattle were inapparently infected or resistant to infection ( 9 ). We describe an H5N1 strain of IAV in dairy cattle that resulted in apparent systemic illness, reduced milk production, and abundant virus shedding in milk. The magnitude of this finding is further emphasized by the high death rate (≈50%) of cats on farm premises that were fed raw colostrum and milk from affected cows; clinical disease and lesions developed that were consistent with previous reports of H5N1 infection in cats presumably derived from consuming infected wild birds ( 10 – 12 ). Although exposure to and consumption of dead wild birds cannot be completely ruled out for the cats described in this report, the known consumption of unpasteurized milk and colostrum from infected cows and the high amount of virus nucleic acid within the milk make milk and colostrum consumption a likely route of exposure. Therefore, our findings suggest cross-species mammal-to-mammal transmission of HPAI H5N1 virus and raise new concerns regarding the potential for virus spread within mammal populations. Horizontal transmission of HPAI H5N1 virus has been previously demonstrated in experimentally infected cats ( 13 ) and ferrets ( 14 ) and is suspected to account for large dieoffs observed during natural outbreaks in mink ( 15 ) and sea lions ( 16 ). Future experimental studies of HPAI H5N1 virus in dairy cattle should seek to confirm cross-species transmission to cats and potentially other mammals.

Clinical IAV infection in cattle has been infrequently reported in the published literature. The first report occurred in Japan in 1949, where a short course of disease with pyrexia, anorexia, nasal discharge, pneumonia, and decreased lactation developed in cattle ( 17 ). In 1997, a similar condition occurred in dairy cows in southwest England leading to a sporadic drop in milk production ( 18 ), and IAV seroconversion was later associated with reduced milk yield and respiratory disease ( 19 – 21 ). Rising antibody titers against human-origin influenza A viruses (H1N1 and H3N2) were later again reported in dairy cattle in England, which led to an acute fall in milk production during October 2005–March 2006 ( 22 ). Limited reports of IAV isolation from cattle exist; most reports occurred during the 1960s and 1970s in Hungary and in the former Soviet Union, where H3N2 was recovered from cattle experiencing respiratory disease ( 9 , 23 ). Direct detection of IAV in milk and the potential transmission from cattle to cats through feeding of unpasteurized milk has not been previously reported.

An IAV-associated drop in milk production in dairy cattle appears to have occurred during > 4 distinct periods and within 3 widely separated geographic areas: 1949 in Japan ( 17 ), 1997–1998 and 2005–2006 in Europe ( 19 , 21 ), and 2024 in the United States (this report). The sporadic occurrence of clinical disease in dairy cattle worldwide might be the result of changes in subclinical infection rates and the presence or absence of sufficient baseline IAV antibodies in cattle to prevent infection. Milk IgG, lactoferrin, and conglutinin have also been suggested as host factors that might reduce susceptibility of bovids to IAV infection ( 9 ). Contemporary estimates of the seroprevalence of IAV antibodies in US cattle are not well described in the published literature. One retrospective serologic survey in the United States in the late 1990s showed 27% of serum samples had positive antibody titers and 31% had low-positive titers for IAV H1 subtype-specific antigen in cattle with no evidence of clinical infections ( 24 ). Antibody titers for H5 subtype-specific antigen have not been reported in US cattle.

The susceptibility of domestic cats to HPAI H5N1 is well-documented globally ( 10 – 12 , 25 – 28 ), and infection often results in neurologic signs in affected felids and other terrestrial mammals ( 4 ). Most cases in cats result from consuming infected wild birds or contaminated poultry products ( 12 , 27 ). The incubation period in cats is short; clinical disease is often observed 2–3 days after infection ( 28 ). Brain tissue has been suggested as the best diagnostic sample to confirm HPAI virus infection in cats ( 10 ), and our results support that finding. One unique finding in the cats from this report is the presence of blindness and microscopic lesions of chorioretinitis. Those results suggest that further investigation into potential ocular manifestations of HPAI H5N1 virus infection in cats might be warranted.

The genomic sequencing and subsequent analysis of clinical samples from both bovine and feline sources provided considerable insights. The HA and NA sequences derived from both bovine milk and cat tissue samples from different Texas farms had a notable degree of similarity. Those findings strongly suggest a shared origin for the viruses detected in the dairy cattle and cat tissues. Further research, case series investigations, and surveillance data are needed to better understand and inform measures to curtail the clinical effects, shedding, and spread of HPAI viruses among mammals. Although pasteurization of commercial milk mitigates risks for transmission to humans, a 2019 US consumer study showed that 4.4% of adults consumed raw milk > 1 time during the previous year ( 29 ), indicating a need for public awareness of the potential presence of HPAI H5N1 viruses in raw milk.

Ingestion of feed contaminated with feces from wild birds infected with HPAI virus is presumed to be the most likely initial source of infection in the dairy farms. Although the exact source of the virus is unknown, migratory birds (Anseriformes and Charadriiformes) are likely sources because the Texas panhandle region lies in the Central Flyway, and those birds are the main natural reservoir for avian influenza viruses ( 30 ). HPAI H5N1 viruses are well adapted to domestic ducks and geese, and ducks appear to be a major reservoir ( 31 ); however, terns have also emerged as an important source of virus spread ( 32 ). The mode of transmission among infected cattle is also unknown; however, horizontal transmission has been suggested because disease developed in resident cattle herds in Michigan, Idaho, and Ohio farms that received infected cattle from the affected regions, and those cattle tested positive for HPAI H5N1 ( 33 ). Experimental studies are needed to decipher the transmission routes and pathogenesis (e.g., replication sites and movement) of the virus within infected cattle.

In conclusion, we showed that dairy cattle are susceptible to infection with HPAI H5N1 virus and can shed virus in milk and, therefore, might potentially transmit infection to other mammals via unpasteurized milk. A reduction in milk production and vague systemic illness were the most commonly reported clinical signs in affected cows, but neurologic signs and death rapidly developed in affected domestic cats. HPAI virus infection should be considered in dairy cattle when an unexpected and unexplained abrupt drop in feed intake and milk production occurs and for cats when rapid onset of neurologic signs and blindness develop. The recurring nature of global HPAI H5N1 virus outbreaks and detection of spillover events in a broad host range is concerning and suggests increasing virus adaptation in mammals. Surveillance of HPAI viruses in domestic production animals, including cattle, is needed to elucidate influenza virus evolution and ecology and prevent cross-species transmission.

Dr. Burrough is a professor and diagnostic pathologist at the Iowa State University College of Veterinary Medicine and Veterinary Diagnostic Laboratory. His research focuses on infectious diseases of livestock with an emphasis on swine.

Acknowledgment

We thank the faculty and staff at the ISUVDL who contributed to the processing and analysis of clinical samples in this investigation, the veterinarians involved with clinical assessments at affected dairies and various conference calls in the days before diagnostic submissions that ultimately led to the detection of HPAI virus in the cattle, and the US Department of Agriculture National Veterinary Services Laboratory and NAHLN for their roles and assistance in providing their expertise, confirmatory diagnostic support, and communications surrounding the HPAI virus cases impacting lactating dairy cattle.

• Caliendo  V , Lewis  NS , Pohlmann  A , Baillie  SR , Banyard  AC , Beer  M , et al. Transatlantic spread of highly pathogenic avian influenza H5N1 by wild birds from Europe to North America in 2021. Sci Rep . 2022 ; 12 : 11729 . DOI PubMed Google Scholar
• Bevins  SN , Shriner  SA , Cumbee  JC Jr , Dilione  KE , Douglass  KE , Ellis  JW , et al. Intercontinental movement of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4 virus to the United States, 2021. Emerg Infect Dis . 2022 ; 28 : 1006 – 11 . DOI PubMed Google Scholar
• Puryear  W , Sawatzki  K , Hill  N , Foss  A , Stone  JJ , Doughty  L , et al. Highly pathogenic avian influenza A(H5N1) virus outbreak in New England seals, United States. Emerg Infect Dis . 2023 ; 29 : 786 – 91 . DOI PubMed Google Scholar
• Elsmo  EJ , Wünschmann  A , Beckmen  KB , Broughton-Neiswanger  LE , Buckles  EL , Ellis  J , et al. Highly pathogenic avian influenza A(H5N1) virus clade 2.3.4.4b infections in wild terrestrial mammals, United States, 2022. Emerg Infect Dis . 2023 ; 29 : 2451 – 60 . DOI PubMed Google Scholar
• Bruno  A , Alfaro-Núñez  A , de Mora  D , Armas  R , Olmedo  M , Garcés  J , et al. First case of human infection with highly pathogenic H5 avian influenza A virus in South America: a new zoonotic pandemic threat for 2023? J Travel Med. 2023 ;30:taad032.
• Pulit-Penaloza  JA , Brock  N , Belser  JA , Sun  X , Pappas  C , Kieran  TJ , et al. Highly pathogenic avian influenza A(H5N1) virus of clade 2.3.4.4b isolated from a human case in Chile causes fatal disease and transmits between co-housed ferrets. Emerg Microbes Infect . 2024 ; 2332667 . DOI PubMed Google Scholar
• United States Department of Agriculture Animal and Plant Health Inspection Service . Federal and state veterinary, public health agencies share update on HPAI detection in Kansas, Texas dairy herds. 2024 [ cited 2024 Mar 29 ]. https://www.aphis.usda.gov/news/agency-announcements/federal-state-veterinary-public-health-agencies-share-update-hpai
• Sharma  A , Zeller  MA , Souza  CK , Anderson  TK , Vincent  AL , Harmon  K , et al. Characterization of a 2016–2017 human seasonal H3 influenza A virus spillover now endemic to U.S. swine. MSphere . 2022 ; 7 : e0080921 . DOI PubMed Google Scholar
• Sreenivasan  CC , Thomas  M , Kaushik  RS , Wang  D , Li  F . Influenza A in bovine species: a narrative literature review. Viruses . 2019 ; 11 : 561 . DOI PubMed Google Scholar
• Sillman  SJ , Drozd  M , Loy  D , Harris  SP . Naturally occurring highly pathogenic avian influenza virus H5N1 clade 2.3.4.4b infection in three domestic cats in North America during 2023. J Comp Pathol . 2023 ; 205 : 17 – 23 . DOI PubMed Google Scholar
• Klopfleisch  R , Wolf  PU , Uhl  W , Gerst  S , Harder  T , Starick  E , et al. Distribution of lesions and antigen of highly pathogenic avian influenza virus A/Swan/Germany/R65/06 (H5N1) in domestic cats after presumptive infection by wild birds. Vet Pathol . 2007 ; 44 : 261 – 8 . DOI PubMed Google Scholar
• Keawcharoen  J , Oraveerakul  K , Kuiken  T , Fouchier  RAM , Amonsin  A , Payungporn  S , et al. Avian influenza H5N1 in tigers and leopards. Emerg Infect Dis . 2004 ; 10 : 2189 – 91 . DOI PubMed Google Scholar
• Kuiken  T , Rimmelzwaan  G , van Riel  D , van Amerongen  G , Baars  M , Fouchier  R , et al. Avian H5N1 influenza in cats. Science . 2004 ; 306 : 241 . DOI PubMed Google Scholar
• Herfst  S , Schrauwen  EJA , Linster  M , Chutinimitkul  S , de Wit  E , Munster  VJ , et al. Airborne transmission of influenza A/H5N1 virus between ferrets. Science . 2012 ; 336 : 1534 – 41 . DOI PubMed Google Scholar
• Agüero  M , Monne  I , Sánchez  A , Zecchin  B , Fusaro  A , Ruano  MJ , et al. Highly pathogenic avian influenza A(H5N1) virus infection in farmed minks, Spain, October 2022. Euro Surveill . 2023 ; 28 : 2300001 . DOI PubMed Google Scholar
• Leguia  M , Garcia-Glaessner  A , Muñoz-Saavedra  B , Juarez  D , Barrera  P , Calvo-Mac  C , et al. Highly pathogenic avian influenza A (H5N1) in marine mammals and seabirds in Peru. Nat Commun . 2023 ; 14 : 5489 . DOI PubMed Google Scholar
• Saito  K . An outbreak of cattle influenza in Japan in the fall of 1949. J Am Vet Med Assoc . 1951 ; 118 : 316 – 9 . PubMed Google Scholar
• Gunning  RF , Pritchard  GC . Unexplained sporadic milk drop in dairy cows. Vet Rec . 1997 ; 140 : 488 . PubMed Google Scholar
• Brown  IH , Crawshaw  TR , Harris  PA , Alexander  DJ . Detection of antibodies to influenza A virus in cattle in association with respiratory disease and reduced milk yield. Vet Rec . 1998 ; 143 : 637 – 8 . PubMed Google Scholar
• Crawshaw  TR , Brown  I . Bovine influenza. Vet Rec . 1998 ; 143 : 372 . PubMed Google Scholar
• Gunning  RF , Brown  IH , Crawshaw  TR . Evidence of influenza A virus infection in dairy cows with sporadic milk drop syndrome. Vet Rec . 1999 ; 145 : 556 – 7 . DOI PubMed Google Scholar
• Crawshaw  TR , Brown  IH , Essen  SC , Young  SCL . Significant rising antibody titres to influenza A are associated with an acute reduction in milk yield in cattle. Vet J . 2008 ; 178 : 98 – 102 . DOI PubMed Google Scholar
• Lopez  JW , Woods  GT . Influenza virus in ruminants: a review. Res Commun Chem Pathol Pharmacol . 1984 ; 45 : 445 – 62 . PubMed Google Scholar
• Jones-Lang  K , Ernst-Larson  M , Lee  B , Goyal  SM , Bey  R . Prevalence of influenza A virus (H1N1) antibodies in bovine sera. New Microbiol . 1998 ; 21 : 153 – 60 . PubMed Google Scholar
• Briand  FX , Souchaud  F , Pierre  I , Beven  V , Hirchaud  E , Hérault  F , et al. Highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus in domestic cat, France, 2022. Emerg Infect Dis . 2023 ; 29 : 1696 – 8 . DOI PubMed Google Scholar
• Frymus  T , Belák  S , Egberink  H , Hofmann-Lehmann  R , Marsilio  F , Addie  DD , et al. Influenza virus infections in cats. Viruses . 2021 ; 13 : 1435 . DOI PubMed Google Scholar
• Songserm  T , Amonsin  A , Jam-on  R , Sae-Heng  N , Meemak  N , Pariyothorn  N , et al. Avian influenza H5N1 in naturally infected domestic cat. Emerg Infect Dis . 2006 ; 12 : 681 – 3 . DOI PubMed Google Scholar
• Thiry  E , Zicola  A , Addie  D , Egberink  H , Hartmann  K , Lutz  H , et al. Highly pathogenic avian influenza H5N1 virus in cats and other carnivores. Vet Microbiol . 2007 ; 122 : 25 – 31 . DOI PubMed Google Scholar
• Lando  AM , Bazaco  MC , Parker  CC , Ferguson  M . Characteristics of U.S. consumers reporting past year intake of raw (unpasteurized) milk: results from the 2016 Food Safety Survey and 2019 Food Safety and Nutrition Survey. J Food Prot . 2022 ; 85 : 1036 – 43 . DOI PubMed Google Scholar
• Fourment  M , Darling  AE , Holmes  EC . The impact of migratory flyways on the spread of avian influenza virus in North America. BMC Evol Biol . 2017 ; 17 : 118 . DOI PubMed Google Scholar
• Guan  Y , Smith  GJD . The emergence and diversification of panzootic H5N1 influenza viruses. Virus Res . 2013 ; 178 : 35 – 43 . DOI PubMed Google Scholar
• de Araújo  AC , Silva  LMN , Cho  AY , Repenning  M , Amgarten  D , de Moraes  AP , et al. Incursion of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus, Brazil, 2023. Emerg Infect Dis . 2024 ; 30 : 619 – 21 . DOI PubMed Google Scholar
• American Veterinary Medical Association . States with HPAI-infected dairy cows grows to six. USDA provides guidance for veterinarians, producers on protecting cattle from the virus. 2024 [ cited 2024 Apr 10 ]. https://www.avma.org/news/states-hpai-infected-dairy-cows-grows-six
• Figure 1 . Mammary gland lesions in cattle in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024. A, B) Mammary...
• Figure 2 . Lesions in cat tissues in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024. Tissue sections were stained...
• Figure 3 . Phylogenetic analysis of hemagglutinin gene sequences in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024. Colors indicate...
• Figure 4 . Phylogenetic analysis of neuraminidase gene sequences in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024. Colors indicate...
• Table 1 . Microscopic lesions observed in cattle in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024
• Table 2 . Microscopic lesions observed in cats in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024
• Table 3 . PCR results from various specimens in study of highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024

Suggested citation for this article : Burrough ER, Magstadt DR, Petersen B, Timmermans SJ, Gauger PC, Zhang J, et al. Highly pathogenic avian influenza A(H5N1) clade 2.3.4.4b virus infection in domestic dairy cattle and cats, United States, 2024. Emerg Infect Dis. 2024 Jul [ date cited ]. https://doi.org/10.3201/eid3007.240508

DOI: 10.3201/eid3007.240508

Original Publication Date: April 29, 2024

Table of Contents – Volume 30, Number 7—July 2024

Please use the form below to submit correspondence to the authors or contact them at the following address:

Eric R. Burrough, Iowa State University Veterinary Diagnostic Laboratory, 1937 Christensen Dr, Ames, IA 50011, USA

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