APA (7th ed.) Citation

Koestler, A. (1968). The sleepwalkers ([1st American ed.].). Macmillan.

Chicago Style (17th ed.) Citation

Koestler, Arthur. The Sleepwalkers. [1st American ed.]. New York: Macmillan, 1968.

MLA (9th ed.) Citation

Koestler, Arthur. The Sleepwalkers. [1st American ed.]. Macmillan, 1968.