APA (7th ed.) Citation

Christie, A., Fair, A. A., & Mason, F. v. W. (2002). The body in the library. Harper.

Chicago Style (17th ed.) Citation

Christie, Agatha, A. A. Fair, and F. van Wyck Mason. The Body in the Library. London: Harper, 2002.

MLA (9th ed.) Citation

Christie, Agatha, et al. The Body in the Library. Harper, 2002.