If there is no named author, follow the citation style for the item, and omit the author name field.
If the item is really authored by a person going by the name Anonymous, use the word "Anonymous" as if it were a complete name of the author, and then use the appropriate style.
Author names in all references:
For materials with 1-6 authors or editors, list all author or editor names.
For materials with 7 or more authors or editors, list the first three, then abbreviate with et al.
Capitalization of titles in reference list:
For journal article titles and book chapters: capitalize the first letter of the first word, proper names, names of trials or study groups, and abbreviations.
For titles of books and government documents, capitalize the first letter of each major word, but not articles, prepositions of less than 3 letters, conjunctions, or infinitives.
(note: No guidance is provided regarding capitalization for titles of conference materials, titles of journals, or other titles used in AMA citations.)
Titles of journals:
Use PubMed journal abbreviations. You can find these by using the citing tool within PubMed, or search the NLM Catalog for journal titles to locate the preferred abbreviation. If no abbreviation is found in PubMed or the NLM Catalog, consult section 13.10 of the AMA Manual of Style for standard abbreviations for individual words used in a title.
Non-scholarly or non-peer-reviewed materials appearing in journals (editorials, letters to the editor, comments, interviews, etc.):
Unlike prior editions of AMA style, the 11th edition has removed the suggestion to indicate special types of materials within journals. Cite all materials published in journals using the article style.
Use of Artificial Intelligence (A.I.):
"Nonhuman artificial intelligence, language models, machine learning, or similar technologies cannot be listed as authors because these technologies do not qualify for authorship." (quotation from AMA Manual, section 5.1.12). According to a strict reading of the Manual, AI programs should never appear in a reference list as an author or creator of content. Instead, AMA suggest that writers place an acknowledgement into the acknowledgement section of the manuscript or describe how AI was used in the Methods section of the manuscript. The primary goal of the AMA Manual of Style is to share the official JAMA (Journal of the American Medical Association) guidance for formatting manuscripts for JAMA, so this is helpful in this context. However, it is difficult to put into place in coursework, where assignments typically do not include either an acknowledgements or Methods section. When writing for a class, review the syllabus or speak with the faculty member to determine if you are allowed to use AI tools, then use the guidance on this page to appropriately describe use of AI in your written assignments.
How to cite information when there is no guidance on this website:
This website attempts to summarize over 500 pages of content from the AMA Manual and cannot cover all. Read the AMA Manual of Style, section 3, to find guidance for citing many other types of publications. If there is no guidance in the Manual on your specific type of publication-- which there may be, the Manual does not include everything-- adapt an existing AMA citation style.
General format: Author AA, Author BB, Author CC. Title of article. Abbreviated Title of Journal. Year of publication;volume(issue):complete page numbers or e-locator. DOI (if not provided, omit and replace with an accessed date and a URL)
Note that there is no period at the end of the DOI or URL in online journal article citations.
Print journal article:
Towfighi A, Markovic D, Ovbiagele B. Utility of Framingham coronary disease risk score for predicting cardiac risk after stroke. Stroke. 2012;43(11):2942-2947.
Journal article viewed online with DOI available:
Towfighi A, Markovic D, Ovbiagele B. Utility of Framingham coronary disease risk score for predicting cardiac risk after stroke. Stroke. 2012;43(11):2942-2947. doi: 10.1161/STROKEAHA.112.668319
Journal article viewed online, but the journal does not use DOI:
Ng L, Karunasinghe N, Benjamin CS, Ferguson LR. Beyond PSA: are new prostate cancer biomarkers of potential value to New Zealand doctors? N Z Med J. 2012;125(1353). Accessed April 15, 2020. https://www.nzma.org.nz/journal-articles/beyond-psa-are-new-prostate-cancer-biomarkers-of-potential-value-to-new-zealand-doctors/
"Nonhuman artificial intelligence, language models, machine learning, or similar technologies cannot be listed as authors because these technologies do not qualify for authorship." (quotation from AMA Manual, section 5.1.12). No AI programs should ever appear in the numbered reference list. AMA suggests that writers place an acknowledgement into the acknowledgement section of the manuscript or describe how AI was used in the Methods section of the manuscript. This advice is difficult to put into place in coursework, where assignments typically do not include either an acknowledgements or Methods section. When writing for a class, review the syllabus or speak with the faculty member to determine if you are allowed to use AI tools, then use this guide to get ideas for how to acknowledge the source.
"Section 188.8.131.52 Acknowledgment of Use of Artificial Intelligence and Language Models in Writing and Editing
Authors should report the use of artificial intelligence, language models, machine learning, or similar technologies to create content or assist with writing or editing of manuscripts in the Acknowledgment section or the Methods section if this is part of formal research design or methods. This should include a description of the content that was created or edited and the name of the language model or tool, version and extension numbers, and manufacturer. (Note: this does not include basic tools for checking grammar, spelling, references, etc.)."
Strict interpretation of this for publication in a journal:
In 1-5 sentences, describe what you used AI to do in the manuscript, with enough information to explain the actual model used. Place this in the Methods section if the AI content was important to the methods. Otherwise, place in the Acknowledgements section. The AMA Manual does not provide any examples. Here are two examples created by a USC librarian that attempt to fulfill the AMA rules:
"On August 3, 2023, I used AI to summarize five research papers, to help me determine which idea was least studied and focus my topics for this essay. I used ChatGPT, model 3.5, made by OpenAI, hosted at https://chat.openai.com/."
"I used Bard, release 2023.07.13, made by Google and hosted at https://bard.google.com/, to edit my manuscript. I uploaded my original writing and asked Bard to reduce the word count and make the language more formal. I also used Bard to determine which of the data points I had collected would be the most useful for including as figures, and used its advice to create figure 1 and table 2."
Potential ways to acknowledge use of AI tools in a written document for a course:
There is no guidance on this from the AMA Manual. As typical with this style, when no guidance exists, try to follow the basic rules of the style while respecting the underlying goal of any citation system: to acknowledge the use of other's ideas, thoughts, and opinions. While AI might not be a person, it’s still not you, so its ideas and work needs to be acknowledged. Based on this, here are some options that might work:
- While your assignment may not require you to include a formal Methods section, you could decide to include one anyway. You could describe all the methods used to create this assignment: searching for literature, using modeling software, collaboratively editing with a colleague, etc., alongside how you used AI, and which model you used.
- Add a few sentences about your use of AI and the model (as recommended by AMA) into another section of the assignment. If you used AI to generate ideas, perhaps this acknowledge would fit into the introduction. If you used AI to edit the paper, this might be acknowledged in the conclusion.
- AMA style requires a numbered reference list. You could add an unnumbered bullet point to the start or end of your reference list that acknowledges the use(s) of AI in your assignment and provides the model number as instructed by AMA.
General format: Author AA, Author BB, Author CC. Title of book. Edition number (if beyond first). Publisher name; year of publication. To indicate online access, add the word Accessed and the date you accessed the item, then the URL.
While some books and book chapters may have assigned DOIs, book citations do not include DOIs, only URLs and accessed dates. If a book has editors instead of or in addition to authors, their names are indicated with "eds." after the author field names.
Wasserman K, Hansen JE, Sue DY, et al. Principles of Exercise Testing and Interpretation: Including Pathophysiology and Clinical Applications. 5th ed. Wolters Kluwer Health/Lippincott William and Wilkins; 2012.
Entire edited print book:
Alldredge BK, Corelli RL, Ernst ME, et al., eds. Koda-Kimble and Young’s Applied Therapeutics: The Clinical Use of Drugs. 10th ed. Lippincott Williams and Wilkins; 2013.
Chapter within an edited book in print:
Relling MV, Giacomini KM. Pharmacogenomics. In: Brunton LL, Chabner BA, Knollmann BC, eds. Goodman and Gilman’s The Pharmacological Basis of Therapeutics. 12th ed. McGraw-Hill; 2011: 145-168.
Book viewed online:
Suchmacher M, Geller M. Practical Biostatistics. Elsevier; 2012. Accessed November 5, 2012. https://www.sciencedirect.com/science/book/9780124157941
Edited book viewed online:
Brunton LL, Blumenthal DK, Murri N, Hilal-Danden R, Knollmann BC, eds. Goodman and Gilman’s The Pharmacological Basis of Therapeutics. 12th ed. McGraw-Hill; 2011. Accessed November 4, 2012. https://www.accesspharmacy.com/resourceToc.aspx?resourceID=28
Chapter within an edited book viewed online:
Relling MV, Giacomini KM. Chapter 7. Pharmacogenomics. In: Brunton LL, Blumenthal DK, Murri N, Hilal-Danden R, Knollmann BC, eds. Goodman and Gilman’s The Pharmacological Basis of Therapeutics. 12th ed. McGraw-Hill; 2011. Accessed October 4, 2012. https://www.accesspharmacy.com/content.aspx?aID=16659580
If materials presented at a conference are published elsewhere as a book, issue of a journal, or other medium, AMA instructs you to cite them using that reference style. Only use this style for materials not formally published as part of another publication.
General format: Author AA, Author BB, Author CC. Title of poster. Poster presented at: Name of conference; Month, Day Year; City, State abbreviation.
Pasternak B. Carvedilol vs metoprolol succinate and risk of mortality in patients with heart failure: national cohort study. Paper presented at: European Society of Cardiology Congress; August 31, 2014; Barcelona, Spain.
Morales M, Zhou X. Health practices of immigrant women: indigenous knowledge in an urban environment. Paper presented at: 78th Association for Information Science and Technology Annual Meeting; November 6-10, 2015; St Louis, MO. Accessed March 15, 2016. https://dl.acm.org/doi/10.5555/2857070.2857108
3.13.2 Special Materials: Government or Agency Reports provides this format for citing reports issued by a department or agency of a government.
(1) name of author (if given); (2) title of bulletin in italics; (3) name of issuing bureau, agency, department, or other governmental division; (4) date of publication; (5) page numbers (if specified); (6) publication number (if any); (7) series number (if given); (8) online accessed date (if applicable); and (9) web address (if applicable).
3.15.5 Electronic References:Government/Organization Reports provides this guidance for citing Government/Organization reports: "These reports are treated much like electronic journal and book references: use journal style for articles and book style for monographs."
MMRW is a journal that publishes reports from the US CDC. Based on the rules of AMA Style, you could choose to cite reports from MMWR as a Government Report or a Journal Article. Here is the same report in both styles:
Selik RM, Mokotoff ED, Branson B, Owen SM, Whitmore S, Hall HI. Revised Surveillance Case Definition for HIV Infection- United States, 2014. Centers for Disease Control and Prevention. 2014;1-11: Morbidity and Mortality Weekly Report. Accessed January 5, 2019. https://www.cdc.gov/mmwr/pdf/rr/rr6303.pdf
Selik RM, Mokotoff ED, Branson B, Owen SM, Whitmore S, Hall HI. Revised Surveillance Case Definition for HIV Infection- United States, 2014. MMWR. 2014;63(3):1-11. Accessed January 5, 2019. https://www.cdc.gov/mmwr/pdf/rr/rr6303.pdf
The Government Accountability Office is a federal office charged with assessing the function of federal government. They publish reports in the form of monographs. Based on the rules of AMA Style, you could choose to cite reports from this office as a Government Report or Monograph style:
Covid-19:Federal Efforts Could be Strengthened by Timely and Concerted Actions. United States Government Accountability Office. September 21, 2020. GAO-20-701. Accessed January 5, 2021. https://www.gao.gov/assets/710/709934.pdf
United States Government Accountability Office. Covid-19:Federal Efforts Could be Strengthened by Timely and Concerted Actions. Government Publication Office; 2020. Accessed January 5, 2021. https://www.gao.gov/assets/710/709934.pdf
In citing data from a website, include the following elements, if available, in the order shown:
■ Authors’ surnames and initials, if given, or name of the group who made the site
■ Title of the specific item cited. If none is given, use the name of the organization responsible for the site.
■ Name of the website
■ [Date published]
■ Updated [date]
■ Accessed [date]
■ URL (verify that the link still works as close as possible to publication)
There is no guidance in the Manual on how to separate elements (using periods, commas, semicolons, etc.); the example above is directly copied from the Manual. The examples below use the diacritical marks as shown in one example in the Manual, separating each field with a period.
Warfarin. Drug Information Online: Drugs.com. September 1, 2012. Updated January 23, 2020. Accessed April 15, 2020. https://www.drugs.com/cons/warfarin.html
DrugBank Online. Acetaminophen. DrugBank Online. June 13, 2005. Updated January 5, 2021. Accessed January 5, 2021. https://go.drugbank.com/drugs/DB00316
Package inserts and prescribing information
Name of drug. Type of material. Company Name; year of publication. To indicate online access, add the accessed date and URL.
Lamasil. Package insert. Sandoz Pharmaceutics Corporation; 1993.
Lovenox. Prescribing information. sanofi-aventis U.S. LLC. Accessed April 15, 2020. https://products.sanofi.us/Lovenox/Lovenox.pdf
Drug Monographs. AMA style does not provide rules for citing drug monographs. These are suggested by the Norris Library and were created by adapting the book and website styles, as these contain similar pieces of information.
Print drug monographs
Author AA. Title of monograph being cited. Editor AA, ed. Title of book. Edition (if beyond first). Publisher name; year of publication.
Online drug monographs
Title of monograph. Title of book of monographs. Title of compendia where book is found(only include if different than book title).Published date. Updated date. Accessed date. URL
Lisinopril. McEvoy GK, ed. AHFS Drug Information 2014. American Society of Health-System Pharmacists, Inc.; 2014.
Lisinopril. AHFS DI (Adult and Pediatric). Lexicomp. Updated March 11, 2016. Accessed May 11, 2016. https://online.lexi.com/lco/action/doc/retrieve/docid/complete_ashp/414040
Inventor names, inventor; assignee company, assignee. Title of patent. Patent issued agency and number. Date patent was granted.
Abram AZ, Fuchsuber L, inventors; Stiefel Research Australia, assignee. Foamable suspension gel. US Patent 8,158,109. April 17, 2012.
Note: this example is for a patent that was granted by the US Patent Office. To cite a patent issued by a different patent office, use this same style but replace the words "US Patent" with the issuing body: WIPO Patent. You may instead need to cite a patent application. Use the same style, but replace the words "US Patent" with "US Patent Application."
AMA Style states that personal communications such as phone calls, emails, conversations, etc. are not included in the reference list. However, you should cite these materials parenthetically within the text. Provide the name and highest academic degree of the author, type of communication, and date sent. If this would compromise patient anonymity, replace the name with a title and remove the day of communication.
Individuals on this new experimental drug should not take aspirin. (Sara P. Norris, M.D., email communication, November 3, 2012.)
For all five patients I have seen with this rare disorder, I have prescribed Interferon. (Physician at LAC + USC Healthcare Network, phone call, October 2012).
What is a DOI?:
A DOI is a Digital Object Identifier. It is a series of letters and numbers that identifies a specific online item. Depending on the publisher, DOIs may be registered through international clearinghouses and function as web links or may not. AMA style allows you to choose to display DOIs in references in two ways, with or without the https://. doi:10.1001/jama.2017.13737 and https://doi.org/10.1001/jama.2017.13737 are both acceptable, and used interchangeably throughout the Manual when a DOI is included in a reference. When you discuss a DOI in writing, capital letters are used to denote that this is an abbreviation. When using a DOI in a citation, AMA Style requires all lowercase: doi.
Including words/phrases like "Paper presented at", "Date Accessed," "Date Updated," etc. in the citations:
AMA Style sometimes requires the use of these "helper phrases" in the reference; in other cases, they are used in examples to show you where to place the information and will be deleted in your final completed citation. AMA Style is not particularly consistent nor logical in its choices to include or exclude "helper phrases" in citations. Examine both the example citation format and the worked examples citing a specific item to determine what to include.
Use Online or Print style?
AMA Style requires you to cite the version of an item you read. An article might be available online and in a print journal. If you read the online copy, cite it using the online citation format. If you read the print item, use the print format.
The URL is incredibly long-- do I need to include the whole thing?
AMA Style's main preference is for you to include the entire and functional URL. However, if a URL is very long and breaks across lines, you may remove portions of the lengthy URL as long as the reader would reasonably be able to access the item from the short URL and information from the citation itself.
Here is an example of when and how to edit URLs:
Lisinopril. AHFS DI (Adult and Pediatric). Lexicomp. Updated March 11, 2016. Accessed May 11, 2016. https://online.lexi.com/lco/action/doc/retrieve/docid/complete_ashp/414040
is a citation to a drug monograph appearing in the book AHFS DI (Adult and Pediatric) available on the online database Lexicomp. The URL provided by Lexicomp for this monograph is actually much longer (it is https://online-lexi-com.libproxy1.usc.edu/lco/action/doc/retrieve/docid/complete_ashp/414040?cesid=aNQswQkZlPy&searchUrl=%2Flco%2Faction%2Fsearch%3Fq%3Dlisinopril%26t%3Dname%26va%3Dlisinopril). If you paste the short URL provided in this citation into your browser, you will arrive at the table of contents of the book AHFS DI (Adult and Pediatric) and can then look for the monograph described in this citation (Lisinopril).