1. Altmann, J. (1974). Observational study of behaviour: Sampling methods.Behav. Jour. 49: 227–265.
2. Altmann, J. (1980).Baboon Mothers and Infants, Harvard University Press, Cambridge, Mass.
3. Baldwin, J. D. (1969). The ontogeny of social behaviour of squirrel monkeys (Saimiri sciureus) in a seminatural environment.Folia Primatol. 11: 35–79.
4. Baldwin, J. D. (1986). Behavior in infancy. Exploration and play in Mitchell, G., and Erwin, J. (eds.),Comparative Primate Biology, Vol. 2. Part A. Behavior, Conservation and Ecology, Alan R. Liss, New York, pp. 295–326.
5. Berman, C. M. (1984). Variation in mother-infant relationships. Traditional and nontraditional factors. In Small, M. F., (ed.),Female Primates: Studies by Women Primatologists, Alan R. Liss, New York, pp. 17–36.