1. Allen, G.E.: 1978, Thomas Hunt Morgan: The Man and his Science, Princeton University Press, Princeton.
2. Bain, A.: 1870, Logic, Longman's, Green, Reader and Dyer, London.
3. Baker, H.G.: 1952, 'The Ecospecies – Prelude to Discussion', Evolution 6, 61–68.
4. Baker, J.R.: 1976, 'Julian Sorell Huxley', Biographical Memoirs of Fellows of the Royal Society of London 22, 207–238.
5. Birdsell, J.B.: 1972, 'The Problem of the Evolution of Human Races: Classification or Clines?', Social Biology 19, 136–162.