Chicago: Author-Date

Machine Readable PDF version of Chicago infographic

This system is more common in the sciences and social sciences. Sources are cited in-text. Note how the source is cited in parentheses, with the author’s last name and year of publication included. If there are two or more works by the same author in the same year, distinguish between the two by using letter suffixes (such as “a,” “b,” or “c”). Each in-text citation will correspond to an entry in a reference list in alphabetical order. For in-text references, parentheses should include the author(s) and year, and page numbers when required. The first line in the reference list should be flush with the left margin, with the following lines indented three or four spaces. A general format example (included on the Chicago-style research guide) of this would be: 

In-text author-date information: 

(Author year, page number)

Reference list:

Lastname, Firstname. Date of publication. Title of Item. Publication Information. 
Grazer, Brian, and Charles Fishman. 2015. A Curious Mind: The Secret to a Bigger Life. New York: Simon & Schuster.

Quick Check: