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Citation/Style Guides

Welcome to the Citation/Style Guides research guide.


The Author-Date System has long been used by those in the physical, natural, and social sciences. In this system, sources are briefly cited in the text, usually in parentheses, by author’s last name and date of publication. The short citations are amplified in a list of references, where full bibliographic information is provided.

Each example includes an in-text citation [T] followed by a reference-list entry [R].


Journals vs Magazines: Journals are normally cited by volume and date, while magazines are normally cited by date alone. If in doubt whether a particular periodical is a journal or magazine, use the journal format if the volume number is easily located, and the magazine format if it is not.

Journal with Issue Number Available

T: (Simmons and Becker-Olsen 2006, 161)

R: Simmons, Carolyn, and Karen Becker-Olsen. 2006. Achieving marketing objectives through social sponsorships. Journal of Marketing 70, no. 4:154-169. 

Journal with no Issue Number

T: (Graham 2006, 157)

R: Graham, Sarah. 2006. Impossible to hold: Women and culture in the 1960s. Journal of American Studies 40:156-159.

Article in an Online Journal

Just like print journals, only adding the URL and also the access date in parentheses at the end only if required by your professor or discipline. Include a DOI (Digital Object Identifier) if the journal lists one (see the second example below). If no DOI is available, list a URL.

T: (Hlatky et al. 2002)

R: Hlatky, Mark A., Derek Boothroyd, Eric Vittinghoff, Penny Sharp, and Mary A. Whooley. 2002. Quality-of-life and depressive symptoms in postmenopausal women after receiving hormone therapy. Journal of the American Medical Association 287, no. 5 (February 6),

T: (Kossinets and Watts 2009, 411)

R: Kossinets, Gueorgi, and Duncan J. Watts. 2009. “Origins of Homophily in an Evolving Social Network.” American Journal of Sociology 115:405–50. Accessed February 28, 2010. doi:10.1086/599247.

Article in an Online Database

This is the same as for online journals as listed above, including use of access date. Also include the URL of the main entrance of the database.

T: (Thomas 1956, 71)

R: Thomas, Trevor M. Wales: Land of Mines and Quarries. Geographical Review 46, no. 1 (1956): 59-81.

Entire Website

Websites may be cited in running text ("According to the National Weather Service's website, warmer temperatures may be expected...") instead of in a note, and they are commonly omitted from the reference list as well. The following examples show the more formal version of the citations. Add the date the material was last accessed for time-sensitive data or if you are required.

T: (National Weather Service)

R: National Oceanic and Atmospheric Administration. NOAA's National Weather Service. U.S. Dept. of Commerce. (accessed January 17, 2010).


T: (Reed 2006, 21)

R: Reed, Stanley. 2006. Seeing Past the War. Business Week, August 21.


Newspaper articles may be cited in running text (“As William Niederkorn noted in a New York Times article on June 20, 2002, . . . ”) instead of in a note or an in-text citation, and they are commonly omitted from a bibliography or reference list as well. The following examples show the more formal version of the citations.

T: (Seward 2006)

R: Seward, Zachary. 2006. Colleges Expand Early Admissions. Wall Street Journal. December 14. Eastern edition.

Blog Entry

T: (Posner 2010)

R: Posner, Richard. 2010. “Double Exports in Five Years?” The Becker-Posner Blog, February 21.


 For additional examples, see pages 247-254 in the Turabian Manual (2007). 

Personal Interviews & Films


Personal Interview

Unpublished interviews are best cited in the text, though they occasionally appear in reference lists when they are critical to the writer's argument or frequently cited.

R: Clown, Krusty T. 2007. Interview by Bart Simpson. Tape recording. February 10. Butler University, Indianapolis.

Personal Email or Text Message

E-mail and text messages may be cited in running text and they are rarely listed in a reference list.

T: (John Doe, e-mail message to author, February 28, 2010)


T: (John Doe, pers. comm.)


R: E.T. the Extra-Terrestrial. 1982. Film. Directed by Steven Spielberg. Hollywood: Universal Pictures.

Recorded Film

R: Harry Potter and the Sorcerer’s Stone. 2001. DVD. Directed by Chris Columbus. Hollywood: Warner.

For additional examples, see pages 260-263 and 266 -269 in the Turabian Manual (2007).