1. Armagnac, C., and Retel-Laurenton, A. (1981). Relations between fertility, birth intervals, foetal mortality and maternal health in Upper Volta.Population Studies 35(2): 217?234.
2. Altmann, J. (1980).Baboon Mothers and Infants. Harvard University Press, Cambridge, Massachusetts.
3. Altmann, J., Hausfater, G., Altmann, S. (1988). Determinants of reproductive success in Savannah baboons,Papio cynocephalus. In Clutton-Brock, T. (ed.),Reproductive Success. The University of Chicago Press, Chicago, pp. 403?418.
4. Beckerman, S. (1975). The Cultural Energetics of the Barí of Northern Colombia. Ph.D. dissertation, Department of Anthropology, The University of New Mexico.
5. Beckerman, S. (1976). An unusual live-birth sex ratio in Ecuador.Social Biology 23: 172?174.