1. Als, H. (1975).An ethological study of mother-infant interaction. Unpublished doctoral dissertation, University of Pennsylvania.
2. Alson, D. (1982).Maternal empathy in relation, to infant affective engagement of four months. Unpublished doctoral dissertation Yeshiva University.
3. Bateson, M.C. (1975). Mother-infant exchanges: The epigenesis of conversational interaction.Annals of the New York Academy of Sciences, 263, 101–113.
4. Beebe, B., & Gerstman, L. (1980). The “packaging” of maternal stimulation in relation to infant facial-visual engagement.Merrill-Palmer Quarterly, 26, 321–339.
5. Beebe, B., & Stern, D.N. (1977). Engagement-disengagement and early object experiences. In N. Freedman & S. Grand (Eds.)Communicative structures and psychic structures: A psychoanalytic interpretation of communication. New York: Plenum Press.