1. Amsel, A. Inhibition and mediation in classical, Pavlovian and instrumental conditioning. In R. A. Boakes and M. S. Halliday (Eds.),Inhibition and learning. New York: Academic Press, 1972. Pp. 275–298.
2. Bolles, R. C.Theory of motivation. New York: Harper, 1967.
3. Davis, H. Conditioned suppression: A survey of the literature. Psychonomic Monograph Supplements, 1968, 2(14, Whole No. 30).
4. Denny, M. R. Relaxation theory and experiments. In F. R. Brush (Ed.),Aversive conditioning and learning. New York: Academic Press, 1971. Pp. 235–295.
5. Domber, E. A., Jr. Facilitation and retardation of instrumental appetitive learning by prior Pavlovian aversive conditioning. Unpublished PhD thesis, University of Pittsburgh, 1971.