1. American Psychiatric Association. (1987).Diagnostic and statistical manual of mental disorders (3rd. ed., rev.). Washington, DC.
2. Baron-Cohen, S. (1987). Autism and symbolic play.British Journal of Developmental Psychology, 5, 139–148.
3. Bartak, L., & Rutter, M. (1973). Special educational treatment of autistic children: A comparative study-II. Follow-up findings and implications for services.Journal of Child Psychology and Psychiatry, 14, 241–270.
4. Bates, E. (1976).Language in context: The acquisition of pragmatics. New York: Academic Press.
5. Brazelton, T. B., Koslowski, B., & Main, M. (1974). The origins of reciprocity: the early mother-infant interaction. In M. Lewis & L. A. Rosenblum (Eds.),The effect of the infant on its caregiver (pp. 49–76). New York: Wiley.