1. Oster, G. F. & Wilson, E. O. Caste and Ecology in the Social Insects. Monographs in Population Biology 12. (Princeton University Press, 1978)
2. Fisher, R. A. The Genetical Theory of Natural Selection. (Clarendon, 1930).
3. Kolman, W. A. The mechanism of natural selection for the sex ratio. Am. Nat. 94, 373–377 (1960).
4. Bourke, A. F. G. & Franks, N. R. Social Evolution in Ants. Monographs in Behavior and Ecology. (Princeton University Press, 1995).
5. Jones, S. C., La Fage, J. P. & Howard, R. W. Isopteran sex ratios: phylogenetic trends. Sociobiology 14, 89–156 (1988).