Howard, J. (2001). Darwin: A Very Short Introduction (1st.). Oxford.
Lua i Stíl Chicago (17ú heag.)Howard, Jonathan. Darwin: A Very Short Introduction. 1st. Oxford, 2001.
Lua MLA (9ú heag.)Howard, Jonathan. Darwin: A Very Short Introduction. 1st. Oxford, 2001.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.