1. BERNBERG, R. E. A comparison of the effects of ECS and EN upon the larning ability of young rats. J. comp. physiol. Psychol., 1951, 44, 50-60.
2. DENENBERG, V. H., & BELL, R. W. Critical period for effects of infantile experience on adult learning. Science, 1960, 131, 227-228.
3. DENENBERG, V. H., & KARAS, G. G. Effects of differential infantile handling upon weight gain and morality in the rat and mouse. Science, 1959, 130, 629-630.
4. ERIKSEN, C. W., PORTER, P. B., & STONE, C. P. Learning ability in rats given ECS in late infancy. I. J. comp. physiol. Psychol., 1948, 41, 144-154.
5. LEVINE, S., & LEWIS, G. W. Critical period for the effects of infantile experience on maturation of stress response. Science, 1959, 129, 42-43.