1. Bessemer, D. W., and Stollnitz, F. (1971). Retention of discriminations and an analysis of learning set. In Schrier, A. M., and Stollnitz, F. (eds.),Behavior of Nonhuman Primates (Vol. 4), Academic Press, New York.
2. Fletcher, H. J. (1965). The delayed-response problem. In Schrier, A. M., Harlow, H. F., and Stollnitz, F. (eds.),Behavior of Nonhuman Primates (Vol. I), Academic Press, New York.
3. Harlow, H. F. (1949). The formation of learning sets.Psychol. Rev. 56: 51–65.
4. Meyer, D. R., Treichler, F. R., and Meyer, P. M. (1965). Discrete-trial training techniques and stimulus variables. In Schrier, A. M., Harlow, H. F., and Stollnitz, F. (eds.),Behavior of Nonhuman Primates (Vol. I), Academic Press, New York.
5. Riopelle, A. J. (1954). Facilities of the Emory University Primate Behavior Laboratory.J. Psychol. 38: 331–338.