Cita APA (7a ed.)

Williams, L. (1971). Challenge to survival: A philosophy of evolution. Deutsch.

Cita Chicago Style (17a ed.)

Williams, Leonard. Challenge to Survival: A Philosophy of Evolution. London: Deutsch, 1971.

Cita MLA (8a ed.)

Williams, Leonard. Challenge to Survival: A Philosophy of Evolution. Deutsch, 1971.