↑ Mehmet Bayrakdar, "Al-Jahiz And the Rise of Biological Evolutionism", The Islamic Quarterly, Third Quarter, 1983, London.
↑ Paul S. Agutter & Denys N. Wheatley (2008). Thinking about Life: The History and Philosophy of Biology and Other Sciences. Springer. p. 43. ISBN 1-4020-8865-5
↑ Albertus Magnus. On Animals: A Medieval Summa Zoologica. The Review of Metaphysics | December 01, 2001 | Tkacz, Michael W.