1. Ainsworth, M. Infant-mother attachment and social development: Socialization as a product of reciprocal responsiveness to signals. In M. Richards (Ed.), The integration of the child into the social world. Cambridge, England: Cambridge University Press, 1974, pp. 99–135.
2. Arnold, M. Emotion and personality (2 Vols). New York: Columbia University Press, 1960.
3. Axelrod, J. Neurotransmitters. Scientific American, 1974, 230, 58–71.
4. Ball, W., & Tronick, E. Infant responses to impending collision: Optical and real. Science, 1971, 171, 818–820.
5. Belmont, J. H. Medical-behavioural research in retardation. In N. R. Ellis (Ed.), International review of research in mental retardation (Vol. 5). New York: Academic Press, 1971.