1. Freud, S.: The Interpretation of Dreams. J. Strachey, translator. P. 599 ff. Basic Books. New York. 1955.
2. Freud, S. The Ego and the Id. Sixth printing. Hogarth. London. 1950.
3. Tinbergen, N.: The Study of Instinct. Clarendon Press. Oxford. 1951.
4. Fletcher, R.: Instinct in Man. International. Universities Press. New York. 1957.
5. Tauber, E. S., and Green, M. R.: Pre-logical Experience, Basic Books. New York. 1959.