1. Amsel, A. Partial reinforcement effects on vigor and persistence: Advances in frustration theory derived from a variety of within-subject experiments. In K. W. Spence and J. T. Spence (Eds.). The psychology of learning and motivation. Vol. 1, New York: Academic Press, 1967, Pp. 1–65.
2. Barnes, W., & Tombaugh, T. N. Another failure to obtain negative incentive contrast following reductions in sucrose reward. Psychological Reports, 1973, 33, 801–802.
3. Benefield, R., Oscos, A., & Ehrenfreund, D. Role of frustration in successive positive contrast. Journal of Comparative and Physiological Psychology, 1974, 86, 648–651.
4. Capaldi, E. J. A sequential hypothesis of instrumental learning. In K. W. Spence and J. T. Spence (Eds.), The psychology of learning and motivation. Vol. 1. New York: Academic Press. 1967. Pp. 67–156.
5. Capaldi, E. J. Partial reward either following or preceding consistent reward: A case of reinforcement level. Journal of Experimental Psychology, 1974, 102, 954–962.