1. Atkinson, J. W., & Birch, D. (1978). Introduction to motivation (2nd ed.). New York: Van Nostrand.
2. Berlyne, D. E. (1960). Conflict, arousal, and curiosity. New York: McGraw Hill.
3. Berfyne D. E. (1967). Arousal and reinforcement. In D. E. Levme (Ed.), Nebraska symposium on motivation (pp. 1–110). Lincoln, NB: University of Nebraska Press.
4. Bischof, N. (1975). A systems approach towards the functional connections of attachment and fear. Child Development, 46, 801–817.
5. Bischof N (1989). Das Rätsel Ödipus. München: Piper.