I am not sure if this reference is appropriate under this section. I found this paper useful (Wing and Gould 1979). A hard copy is at the LKL:

Wing, L. and J. Gould (1979). "Severe Impairments of Social Interaction and Associated Abnormalities in Children: Epidemology and Classification." Journal of Autism and Developmental Disorders 9: 11-29.

-- KaskaPorayskaPomsta - 05 Feb 2007 Annalu is responsible for this Topic