Writers in the natural, physical, and social sciences commonly employ a system that links in-text author and date information with a reference list:
(R) Reference List. The first line should begin flush with the left margin, with following lines in the entry
indented five spaces.
(IT) In-Text Author & Date Information Parentheses should enclose in-text references. When page numbers are required, they
should be separated by comma.
The examples cited below illustrate common material formats. Each reference list entry is accompanied by an example of a corresponding parenthetical citation in the text. For more details and many more examples, see chapter 15 of The Chicago Manual of Style, 16th ed. Chicago: The University of Chicago Press, 2010– available in the Library Reference Room
R: Pollan, Michael. 2006. The Omnivore’s Dilemma: A Natural History of Four Meals. New York: Penguin.
IT: (Pollan 2006, 99–100)
Two or more authors
R: Ward, Geoffrey C., and Ken Burns. 2007. The War: An Intimate History, 1941–1945. New York: Knopf.
IT: (Ward and Burns 2007, 52)
For four or more authors, list all of the authors in the reference list; in the text, list only the first author, followed by et al. (“and others”):
(Barnes et al. 2010)
Chapter or other part of a book
R: Kelly, John D. 2010. “Seeing Red: Mao Fetishism, Pax Americana, and the Moral Economy of War.” In Anthropology and Global Counterinsurgency, edited by John D. Kelly, Beatrice Jauregui, Sean T. Mitchell, and Jeremy Walton, 67–83. Chicago: University of
IT: (Kelly 2010, 77)
Chapter of an edited volume originally published elsewhere (as in primary sources)
R: Cicero, Quintus Tullius. 1986. “Handbook on Canvassing for the Consulship.” In Rome: Late Republic and Principate, edited by Walter Emil Kaegi Jr. and Peter White. Vol. 2 of University of Chicago Readings in Western Civilization, edited by John Boyer and Julius Kirshner, 33–46. Chicago: University of Chicago Press. Originally published in Evelyn S. Shuckburgh, trans., The Letters of Cicero, vol. 1 (London: George Bell & Sons, 1908).
IT: (Cicero 1986, 35)
Preface, foreword, introduction, or similar part of a book
R: Rieger, James. 1982. Introduction to Frankenstein; or, The Modern Prometheus, by Mary Wollstonecraft Shelley, xi–xxxvii. Chicago: University of Chicago Press.
IT: (Rieger 1982, xx–xxi)
Book published electronically
If a book is available in more than one format, cite the version you consulted. For books consulted online, list a URL; include an access date only if one is required by your publisher or discipline. If no fixed page numbers are available, you can include a section title or a chapter or other number.
R:Austen, Jane. 2007. Pride and Prejudice. New York: Penguin Classics. Kindle edition.
R: Kurland, Philip B., and Ralph Lerner, eds. 1987. The Founders’ Constitution. Chicago: University of Chicago Press. http://press-pubs.uchicago.edu/founders/.
IT: (Kurland and Lerner, chap. 10, doc. 19)
Article in a print journal
In the text, list the specific page numbers consulted, if any. In the reference list entry, list the page range for the whole article.
R: Weinstein, Joshua I. 2009. “The Market in Plato’s Republic.” Classical Philology 104:439–58.
IT: (Weinstein 2009, 440)
Article in an online journal
Include a DOI (Digital Object Identifier) if the journal lists one. A DOI is a permanent ID that, when appended to http://dx.doi.org/ in the address bar of an Internet browser, will lead to the source. If no DOI is available, list a URL. Include an access date only if one is required by your publisher or discipline.
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.
IT: (Kossinets and Watts 2009, 411)
Article in a newspaper or popular magazine
Newspaper and magazine articles may be cited in running text (“As Sheryl Stolberg and Robert Pear noted in a New York Times article on February 27, 2010, . . .”), and they are commonly omitted from a reference list. The following examples show the more formal versions of the citations. If you consulted the article online, include a URL; include an access date only if your publisher or discipline requires one. If no author is identified, begin the citation with the article title.
R: Mendelsohn, Daniel. 2010. “But Enough about Me.” New Yorker, January 25.
R: Stolberg, Sheryl Gay, and Robert Pear. 2010. “Wary Centrists Posing Challenge in Health Care Vote.” New York Times, February 27. Accessed February 28, 2010. http://www.nytimes.com/2010/02/28/us/politics/28health.html.
IT: (Mendelsohn 2010, 68)
IT: (Stolberg and Pear 2010)
R: Kamp, David. 2006. “Deconstructing Dinner.” Review of The Omnivore’s Dilemma: A Natural History of Four Meals, by Michael
R: Pollan. New York Times, April 23, Sunday Book Review. http://www.nytimes.com/2006/04/23/books/review/23kamp.html.
IT: (Kamp 2006)
Thesis or dissertation
R: Choi, Mihwa. 2008. “Contesting Imaginaires in Death Rituals during the Northern Song Dynasty.” PhD diss., University of Chicago.
IT: (Choi 2008)
Paper presented at a meeting or conference
R: Adelman, Rachel. 2009. “ ‘Such Stuff as Dreams Are Made On’: God’s Footstool in the Aramaic Targumim and Midrashic Tradition.” Paper presented at the annual meeting for the Society of Biblical Literature, New Orleans, Louisiana, November 21–24.
A citation to website content can often be limited to a mention in the text (“As of July 19, 2008, the McDonald’s Corporation listed on its website . . .”). If a more formal citation is desired, it may be styled as in the examples below. Because such content is subject to change, include an access date or, if available, a date that the site was last modified. In the absence of a date of publication, use the access date or last-modified date as the basis of the citation.
R: McDonald’s Corporation. 2008. “McDonald’s Happy Meal Toy Safety Facts.” Accessed July 19. http://www.mcdonalds.com/corp/about/factsheets.html.
IT: (Google 2009)
IT: (McDonald’s 2008)
Blog entry or comment
Blog entries or comments may be cited in running text (“In a comment posted to The Becker-Posner Blog on February 23, 2010, . . .”), and they are commonly omitted from a reference list. If a reference list entry is needed, cite the blog post there but mention comments in the text only. (If an access date is required, add it before the URL; see examples elsewhere in this guide.)
R: Posner, Richard. 2010. “Double Exports in Five Years?” The Becker-Posner Blog, February 21. http://uchicagolaw.typepad.com/beckerposner/2010/02/double-exports-in-five-years-posner.html.
IT: (Posner 2010)
Information and Examples provided by The Chicago Manual of Style 16th Online Edition.
The University of Chicago . "The Chicago Manual of Style Online: Chicago-Style Citation Quick Guide." The Chicago Manual of Style Online. http://www.chicagomanualofstyle.org/tools_citationguide.html (accessed July 19, 2012).