1. AL-ISSA, I. The effect of attitudinal factors on conditioning. In H. J. Eysenck (Ed.), Experiments in motivation. New York: The Macmillan Co., 1964. Pp. 223–282.
2. CAMPBELL, A. A. The interrelations of two measures of conditioning in man. J. exp. Psychol., 1938, 22, 225–243.
3. CAMPBELL, A. A., & HILGARD, E. R. Individual differences in ease of conditioning. J. exp. Psychol., 1936, 19, 561–571.
4. FRANKS, C. M. Personality and eyeblink conditioning seven years later. Acta psychol., Amsterdam, 1963, 21, 295–312.
5. KIMBLE, G. A., LEONARD, T. B., & PERLMUTER, L. C. Eyelid conditioning and US intensity. Paper presented at Midwest. Psychol. Assoc., St. Louis, 1966.