1. Alcock, J. (1980) Natural selection and mating systems of solitary bees. Am. Sci. 68: 146–153.
2. Alcock, J. and Houston, T. F. (1987) Resource defense and alternative mating tactics in the Banksia bee, Hylaeus alcyoneus (Erichson). Ethology 76: 177–188.
3. Alexander, R. D., Hoogland, f. L., Howard, R. D., Noonan, K. M. and Sherman, P. W. (1979) Sexual dimorphism and breeding systems in pinnipeds, ungulates, primates, and humans, in Evolutionary Biology and Human Social Behavior: 432–435 (N. A. Chagnon and W. Irons, eds), North Scituate: Duxbury Press.
4. Barash, D. P. (1974) The social behaviour of the hoary marmot (Marmota caligata). Anim. Behav. 22: 256–261.
5. Barlow, G. W. (1972) A paternal role for bulls of the Galapagos sea lion. Evolution 26: 307–310.