APA (7th ed.) Citation

Russell, B. R. (1956). Our knowledge of the external world (2nd ed.). New American Library.

Chicago Style (17th ed.) Citation

Russell, Bertrand Russell. Our Knowledge of the External World. 2nd ed. [New York]: New American Library, 1956.

MLA (9th ed.) Citation

Russell, Bertrand Russell. Our Knowledge of the External World. 2nd ed. New American Library, 1956.