Cita APA (7th ed.)

Huxley, J. (1939). Essays of a Biologist. Penguin Books.

Cita Chicago (17th ed.)

Huxley, Julian. Essays of a Biologist. Harmondsworth: Penguin Books, 1939.

Cita MLA (8th ed.)

Huxley, Julian. Essays of a Biologist. Penguin Books, 1939.