1. Field Observations on a Howling Monkey Society
2. The composition and properties of gum exudates from subspecies of Acacia tortilis
3. (1978) Medicinal Plants of West Africa. Algonac, Michigan: Reference Publications, Inc.
4. and (1975) Studies of nectar-constitution and pollinator-plant coevolution. In and (eds): Coevolution of Animals and Plants. Austin: University of Texas Press, pp. 100-140.
5. Population density and use of space in howling monkeys (Alouatta villosa) in southwestern Panama