1. Bandura, M. The effects of an operant conditioning experiment on the social behavior of a captive group of diana monkeys. Paper presented at the Western Psychological Association meeting, April, 1974.
2. Chasan, D. In this zoo, visitors learn, though no more than animals. Smithsonian 5(4): 1974.
3. Olivers, D. The siamang and gibbon in the Malay Peninsula. In Rumbaugh, D. (Ed.) Gibbon and Siamang. Basel: S. Karger, 1972.
4. Grzimek, B. Animal Life Encyclopedia, Vol. 12. New York: Van Nostrand Reinhold, 1972.
5. Hancocks, D. Behavioral engineering in the zoo: A critique. Paper presented at the 53rd Annual AAZPA Conference, San Diego, September, 1977.