The Chicago Style consists of two different systems:
- the first, for the humanities, is often used in history. Bibliographic references are given in notes (footnotes or endnotes), with or without a full bibliography at the end of the text.
- The second system, the author-date system, is used in the social sciences. Sources are cited in the text, usually in parentheses, with the author’s surname, the date of publication of the work cited, and a page number if necessary. Full details appear in the bibliography - usually entitled "References" or "Works Cited" - where the year of publication appears immediately after the author’s name.