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AMA Style - 11th Edition

Referencing guide for the 11th Edition of AMA Style

Authors - format and numbers

Author formats in the Reference List

The authors follow the pattern of Surname Initials (e.g. Brown JA) and are separated by a comma.

If there are six authors/editors or less, include the names of all authors/editors.

If there are more than six authors/editors, only list the first three names, then shorten with et al. (e.g. Smith AA, Jones BA, Bloggs JC, et al.).

  1. Hallal AH, Amortegui JD, Jeroukhimov IM, et al. Magnetic resonance cholangiopancreatography accurately detects common bile duct stones in resolving gallstone pancreatitis. J Am Coll Surg. 2005;200(6):869-75.

Mentioning the authors by name in text

In narrative citations in text, you mention the author's names as part of the sentence. Place the reference number next to the author's names. For example:

Research conducted by Smith7 showed a correlation between...

When you have only two authors, you will always mention both authors in the sentence:

Research conducted by Smith and Green7 showed a correlation between...

If you have three or more authors, give the first author and et al (note that for AMA you do not put a full stop after al in et al):

Research conducted by Smith et al7 showed a correlation between...

No author

In certain instances, an article may not have an author. Start the reference with the title, in these cases. In other instances, the author may remain anonymous. However, the word “Anonymous” should not be used in a reference unless that word was published in the article’s byline. Note: There is no need to repeat the word “Anonymous” to represent a first name and a surname.

  1. Incorrect percentages in the abstract. JAMA Oncol. 2017;3(12):1742. doi:10.1001/jamaoncol.2017.4368

  2. Anonymous. Care can’t get better until complaints are heard. BMJ. 2012;345:e4511. doi:10.1136/bmj.e4511


Corporate author

If a group or corporation is acting as the author of a work, and there are no individually listed authors, use the name of the group as your author.

  1. World Health Organization. WHO Guideline on Use of Ferritin Concentrations to Assess Iron Status in Individuals and Populations. World Health Organization; 2020.

Note: rules may differ for websites.