There are several versions of Chicago style, including Turabian style, which is a simplified version keyed toward students. Humanities disciplines frequently make use of the Notes and Bibliography system (NB), which allows writers to make footnotes and other commentary. Social sciences disciplines tend to use the Author-Date system.
The Notes and Bibliography system requires that each in-text reference includes a number corresponding to a footnote.
From the Purdue Owl site:
- Note numbers should begin with “1” and follow consecutively throughout a given paper.
- In the text, note numbers are superscripted.
- Note numbers should be placed at the end of the clause or sentence to which they refer and should be placed after any and all punctuation.
- In the notes themselves, note numbers are full-sized, not raised, and followed by a period (superscripting note numbers in the notes themselves is also acceptable).
- The first line of a footnote is indented .5” from the left margin.
- Subsequent lines within a footnote should be formatted flush left.
- Leave an extra line space between footnotes.
- Place commentary after documentation when a footnote contains both, separated by a period.
- In parenthetical citation, separate documentation from brief commentary with a semicolon.
- Do not repeat the hundreds digit in a page range if it does not change from the beginning to the end of the range.
More information on the Notes Bibliography system (OWL Purdue).
In the Author-Date system, citations are placed into parentheses in the text in this order: author last name year of publication, page number, and then fully cited in the References section.
- Example: (Mueller 2014, 19)
- Multiple authors may be listed, or acknowledged with et al.
- Example: (Bennett, Sanders, and Lee 1998, 238)
- Example: (Bennett et al. 1998, 238)
More information on Author Date system (OWL Purdue).
More information on Author Date system (Trinity University).
- Notes and Bibliography references list should be named "Bibliography;" Author-Date style references should be named "References."
- Bibliographies / Reference lists should be in alphabetical order by the first letter in the first word of each entry.
- Write out names of first 3 authors.
- First author's name is inverted.
- If there are more than three but up to ten authors, write out the names of each author in the reference entry, but use First Author name et al in the in-text citations.
- Titles are headling style (title case); important words are capitalized and less important words are lower-case.
- Larger works e.g. book or journal are italicized.
- Smaller works e.g. book chapter, journal article are placed in "quotation marks".
- Use DOIs instead of URLs, if possible.
- Make DOIs active. See book examples from The Chicago Manual of Style Online. (VPN needed)
Basic Format for a Book in a Bibliography
Last name, First name. Title. Place of publication: Publisher, Year of Publication.
See examples at Notes and bibliography - examples and variation (CMoS)
Basic Format for a Journal Article in a Bibliography
See Access dates for journal articles (CMoS) for an example. Access dates are not required.