1. Aman, M.G., & Sing, N.N. (1982). Methylphenidate in severely retarded residents and the clinical significance of stereotypic behavior.Applied Research in Mental Retardation, 3, 345?358.
2. American Psychiatric Association (1980).Diagnostic and statistical manual of mental disorders (3rd ed.). Washington, DC: Author.
3. American Psychiatric Association. (1987).Diagnostic and statistical manual of mental disorders (3rd ed., rev.). Washington, DC: Author.
4. American Psychiatric Association. (1991).DSM-IV Options Book: Work in progress. Washington, DC: Author.
5. Baird, G., Baron-Cohen, S., Bohman, M., Coleman, M., Frith, U., Gillberg, I. C., Gillberg, C., Howlin, P., Mesibov, G., Peeters, T., Ritvo, E., Steffenburg, S., Taylor, D., Waterhouse, L., Wing, L. & Zapella, M. (1991). Autism is not necessarily a pervasive developmental disorder.Developmental Medicine and Child Neurology, 33, 363?364.