Cita APA (7a ed.)

Koestler, A., & Hardy, D. (1956). Darkness at Noon. Signet book.

Cita Chicago Style (17a ed.)

Koestler, Arthur, y Daphne Hardy. Darkness at Noon. New York: Signet book, 1956.

Cita MLA (9a ed.)

Koestler, Arthur, y Daphne Hardy. Darkness at Noon. Signet book, 1956.