Most authors choose the system used by others in their field or required by their publisher. Follow the links at the top of this page to see examples of some of the more common source types cited in both systems.

Each in-text citation matches up with an entry in a reference list, where full bibliographic information is provided.Īside from the use of numbered notes versus parenthetical references in the text, the two systems share a similar style. In this system, sources are briefly cited in the text, usually in parentheses, by author’s last name and year of publication. The author-date system is more common in the sciences and social sciences. The notes and bibliography system can accommodate a wide variety of sources, including unusual ones that don’t fit neatly into the author-date system. Sources are also usually listed in a separate bibliography. Each note corresponds to a raised (superscript) number in the text. In this system, sources are cited in numbered footnotes or endnotes. The notes and bibliography system is preferred by many working in the humanities-including literature, history, and the arts.

If you are unsure about which system to use, read on. If you already know which system to use, follow one of the links above to see sample citations for a variety of common sources. Chicago-style source citations come in two varieties: (1) notes and bibliography and (2) author-date.

Chicago style footnotes example