1. American Psychiatric Association (2000). Diagnostic and statistical manual of mental disorders (4th ed.), Text Revision (DSM-IV-TR). Washington, DC: Author
2. Arnold G. L., Hyman S. L., Mooney R., Kirby R. S., (2003). Plasma amino acids profiles in children with autism: Potential risk for nutritional deficiencies Journal of Autism and Developmental Disorders 33(4):449–454
3. Bzoch K., League R., (1970). The receptive-expressive emergent language scale for the measurement of language skills in infancy. Gainesville, FL: The Tree of Life Press
4. Cade R., Privette M., Fregley M., Rowland N., Sun Z., Zele V., et al., (1999). Autism and schizophrenia: Intestinal disorders Nutritional Neuroscience 3:57–72
5. Carr E. G., (1985). Behavioral approaches to communication in autism. In Schopler E., Mesibov G., (Eds.), Communicative problems in autism. Plenum Press, New York