"The Chicago Manual of Style" is a commonly accepted stylebook used by scholars in the humanities and social sciences. It provides specific instructions on how to cite a textbook in a paper.
Footnote or Endnote
The proper format for citing your source in the notes is as follows: 1. First name Last name, Title (in italics) (Place of publication: Publisher, Year of publication), page number.
If there are two or three authors, include them all, but follow the same format. Here is an example: Saundra K. Ciccarelli and J. Noland White, Psychology, 3rd Edition (in italics) (New Jersey: Pearson Prentice Hall, 2011), 125.
With four or more authors, everything is the same except that you don't list all authors. Instead, you cite only the name of the first listed author, followed by "et al," which means "and others."
The format is slightly different when creating a bibliography. The last name comes first for the first author listed and parentheses are not needed. It will look like this: Ciccarelli, Saundra K. and J. Noland White. Psychology, 3rd Edition (in italics). New Jersey: Pearson Prentice Hall, 2011.
When you have four or more authors, you will list all of them in the bibliography using the same format as you would for one, two or three authors.