Chicago Manual of Style offers the option to use footnotes, endnotes or parenthetical in-text citations featuring an author / date format. Footnotes or endnotes allow for citation information to be easily accessible at the bottom of each page (footnotes) or at the end of the paper (endnotes). Notes also allow for supplemental explanatory text to be included in the paper at the place it is most relevant. The notes format is used primarily in the disciplines of the humanities (history, religion, philosophy, art, etc.). The author / date format is used primarily in the disciplines of the physical, natural and social sciences (biology, chemistry, sociology, etc.).
The author / date format is similar to MLA and APA citation styles. The following sample papers present all three formats.
Footnotes, which are located at the bottom of each page, acknowledge which parts of the paper reference particular sources. Footnotes should match with a superscript number at the end of the sentence referencing the source. Footnotes should begin with 1 and continue numerically throughout the paper. Do not start the order over on each page.
Author / date in-text citations 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.