1. Fenichel, O.The Psychoanalytic Theory of Neurosis.New York: W. W. Norton, 1945.
2.
2. Hendrick, I.Early development of the ego: identification in infancy. Psychoanal. Quart., 20:44–61, 1951.
3.
3. Kris, E.Laughter as an expressive process: contributions to the psychoanalysis of expressive behavior. Chapter 9 in: Psychoanalytic Explorations in Art.New York: International Universities Press, 1952.
4.
4. Spitz, R. A. and Wolf, K. M.The smiling response: a contribution to the ontogenesis of social relations. Genet. Psychol. Mon., 34, 1946.
5.
5. Webster's New Collegiate Dictionary. Springfield: Merriam, 1951.
