The first time you cite a source, the note should include publication information for that work as well as the page number on which the passage being cited may be found.
FIRST NOTE FOR A SOURCE
1. Peter Burchard, One Gallant Rush: Robert Gould Shaw and His Brave Black Regiment (New York: St. Martin’s, 1965), 85.
For subsequent references to a source you have already cited, you may simply give the author’s last name, a short form of the title, and the page or pages cited. A short form of the title of a book is italicized; a short form of the title of an article is put in quotation marks.
SUBSEQUENT NOTE FOR THE SOURCE
4. Burchard, One Gallant Rush, 31.
If you include a bibliography, The Chicago Manual of Style suggests that you shorten all notes, including the first reference to a source, as in the preceding example. Check with your instructor, however, to see whether using an abbreviated note for a first reference to a source is acceptable.
When you have two consecutive notes from the same source, you may use “Ibid.” (meaning “in the same place”) and the page number for the second note. Use “Ibid.” alone if the page number is the same.
NOTES FOR CONSECUTIVE SOURCES
5. Jack Hurst, Nathan Bedford Forrest: A Biography (New York: Knopf, 1993), 8.
6. Ibid., 174.
Directory to Chicago (CMS) notes and bibliography entries