5Beukelman D, Mirenda P.Augmentative and alternative communication:management of severe communication disorders in children and adults(2nd ed.) .Baltimore: Paul H. Brookes Pr, 1998
6American Psychiatric Association. Diagnostic and statistical manual of mental disorders (DSM-Ⅳ), (4^th ed, text revision). Washington DC,2000
7Wing L, Attwood A .Syndromes of autism and atypical development. Handbook of Autism and Pervasive Developmental Disorders,2001.3--19
8Wetherby M, Prizant B M, HutchinsonT. Communicative, social/affective, and symbolic profiles of young children with autism and pervasive developmental disorders. American Journal of Speech - Language Pathology, 1998,7 : 79 - 91
9Durand, M. Functional communication training using assistive devices:recruiting natural communities of reinforcement. Journal of Applied Behavior Analysis,1999,32:246 - 267