1. (1980). Baboon Mothers and Infants. Cambridge, Mass.: Harvard University Press.
2. Some factors envolved in natural weaning processes in sheep
3. (1973). Plasma testosterone levels in male mice and rats treated with inhibitors of prolactin release. Acta Endocrinol., Suppl. 177, Abstract 22.
4. (1981). Discontinuities in development and changes in the organization of play in cats. In and (eds.), Behavioral Development: The Bielefeld Interdisciplinary Project. New York: Cambridge University Press.