Huxley, J. (1939). Essays of a Biologist. Penguin Books.
Lua i Stíl Chicago (17ú heag.)Huxley, Julian. Essays of a Biologist. Harmondsworth: Penguin Books, 1939.
Lua MLA (8ú heag.)Huxley, Julian. Essays of a Biologist. Penguin Books, 1939.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.