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Citation/Style Guides

Welcome to the Citation/Style Guides research guide.


The Chicago Manual of Style presents two basic documentation systems, the Humanities style (notes and bibliography) and the Author-Date system. Choosing between the two often depends on subject matter and nature of sources cited, as each system is favored by different groups of scholars.

The Humanities style is preferred by many in literature, history, and the arts. This style presents bibliographic information in notes and, often, a bibliography. It accommodates a variety of sources, including esoteric ones less appropriate to the author-date system.

The more concise 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.

The two dropdown pages provide some common examples of materials cited in both styles. 

Online sources that are analogous to print sources (such as articles published in online journals, magazines, or newspapers) should be cited similarly to their print counterparts but with the addition of a URL. Some publishers or disciplines may also require an access date. For online or other electronic sources that do not have a direct print counterpart (such as an institutional Web site or a Weblog), give as much information as you can in addition to the URL.


The most recent editions of Turabian's A Manual for Writers and The Chicago Manual of Style are kept on the Reference shelves on the main floor of Rickman Library.

The Chicago Manual of Style. 17th ed. Chicago: University of Chicago Press, 2017. REF 808.027 C432 2017 

Turabian, Kate L. A Manual for Writers of Research Papers, Theses, and Dissertations: Chicago Style for Students and Researchers. 9th ed. Chicago: University of Chicago Press, 2018. REF 808.02 T865 2018


Why doesn't everyone use the same style?

Not only does source citation give proper credit to the origin of an idea, quote, or fact, it also helps the reader by giving information about the author(s) and/or editor, quality of the source, how long ago it was published, and where it was published.  If the reader wants to study the topic further, all the information necessary to retrieve the original source should be easily available.

Different scholarly readers have different interests which have led to the diversity of documentation styles.  For example, in business, education, and the social sciences, the date of publication and the author is very important to the reader.  Therefore, in-text parenthetical citations used in those disciplines tend to include the year of publication (e.g. APA). 

Some scientific publications often use a style of numbering the works cited and then placing the number in the text as a superscript (e.g. CSE style).  If the author or year is important to the discussion, the writer has the option of putting that information in the sentence itself.

In scholarship associated with disciplines in the humanities, publication date is not as relevant in the context of reading.  Therefore, the documentation style of the Modern Languages Association (MLA) leaves out the date when citing in the text.  That information can be retrieved in the “works cited” list at the end of the document.

Some disciplines, such as History and Religion, require comment on the sources or additional explanation.  To expedite this need without disrupting the reading of the document, citations occur in the form of notes at the bottom of the page.  These disciplines may use the Chicago Manual of Style (CMOS) or similar styles.  Additionally, in these disciplines a Bibliography of all works consulted is helpful to the scholarly reader, as opposed to just a listing works cited in the document.