1. Black, R. W., & Black, P. E. 1967 Heart rate conditioning as a function of interstimulus interval in rats. Psychonomic Science, 8, 219-220.
2. Brush, F. R. 1971 Retention of aversively motivated behavior. In F. R. Brush (Ed.), Aversive-conditioning and learning. New York: Academic Press. Pp.402-465.
3. Brush, F. R., & Levine, S. 1966 Adrenocortical activity and avoidance learning as a function of time after fear conditioning. Physiology and Behavior, 1, 309-311.
4. de Toledo, D., & Black, A. H. 1966 Heart rate: Changes during conditioned suppression in rats. Science, 152, 1404-1406.
5. Fehr, F. S., & Stern, J. A. 1965 Heart rate conditioning in the rat. Journal of Psychosomatic Medicine, 8, 441-453.