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AMA Style: Citing Your Sources: Citing Online Materials

Use AMA Style (American Medical Association Style) to format papers.

is this an online book or web site?

Just because you are viewing the item online, doesn't mean it's a web site.

Online or electronic books are published once and are revised on a set schedule. Online books usually have a print equivalent that contains the exact same information, but in a print form. Usually, these require payment to access. USC Libraries license many electronic books for use by USC students, staff and faculty. 

Electronic journals are also published on a set schedule (usually monthly or quarterly). These also have print equivalents and require payment to access. USC Libraries license many electronic journals for use by USC affiliates.

Web sites are published once, then updated as information is developed or discovered. Web sites do not have a print equivalent. USC Libraries do license some web sites for use by affiliates, but the majority of web sites are free to all.

Citing and Writing Handouts

Online Materials

For electronic or online materials, citations are similar to print, but will include a DOI (Digital Object Identifier) or a URL and the date the material was viewed. DOI is preferred over URL. Most electronic journal articles will include a DOI. It is rare for an electronic book or web site to use DOIs.

Electronic 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. doi: 10.1161/STROKEAHA.112.668319. Accessed November 8, 2012.

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). http://journal.nzma.org.nz/journal/125-1353/5146/. Accessed November 2, 2012.

Electronic book:

Suchmacher M, Geller M. Practical Biostatistics. London, England: Elsevier; 2012. http://www.sciencedirect.com/science/book/9780124157941. Accessed November 5, 2012.

Electronic edited book:

Brunton LL, Blumenthal DK, Murri N, Hilal-Danden R, Knollmann BC, eds. Goodman and Gilman’s The Pharmacological Basis of Therapeutics. 12th ed. New York, NY: McGraw-Hill; 2011. http://www.accesspharmacy.com.libproxy.usc.edu/resourceToc.aspx?resourceID=28. Accessed November 4, 2012.

Chapter within an electronic edited book:

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. New York, NY: McGraw-Hill; 2011. http://www.accesspharmacy.com/content.aspx?aID=16659580. Accessed October 4, 2012.

Web site:

Warfarin. Drug Information Online: Drugs.com. http://www.drugs.com/cons/warfarin.html. Published 2012. Updated date unavailable. Accessed November 8, 2012. 

Tips for Citations

Capitalization of titles in references:

For all titles in citations, retain the original spelling, abbreviations, and capitalization as originally published.

If no original capitalization is available, follow these rules:

Book titles: capitalize all major words. Do not capitalize the, an, a, in, for, or but, unless this word begins the title. Acronyms (NIH, HIV, etc.) should be shown in all caps. 

Chapter titles within books: capitalize only the first word. Acronyms (NIH, HIV, etc.) should be shown in all caps.

Journal titles: capitalize all major words. Do not capitalize the, an, a, in, for, or but, unless this word begins the title. Acronyms (NIH, HIV, etc.) should be shown in all caps. 

Journal article titles: capitalize only the first word. Acronyms (NIH, HIV, etc.) should be shown in all caps. 

Personal communications:

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 parenthentically 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.

Examples:

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).

Anonymous works:

Follow the citation style for book, journal, web site, etc., and omit the author name. 

Non-scholarly materials appearing in journals (editorials, letters to the editor, comments, interviews, etc.):

Include the article type in [brackets] after the title.

Example:

Boden WE, Roberts WC. Williams Edward Boden, MD: a conversation with the editor [Interview]. Am J Cardiol. 2012;110(1):145-159.

How to cite information when there is no guidance on this website:

Read the AMA Manual of Style, section 3, to find guidance for citing many other types of publications and information.

If there is no guidance on your specific type of information, adapt an existing AMA citation style.