1. American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: American Psychiatric Association.
2. Bishop, S., Guthrie, W., Coffing, M., & Lord, C. Convergent validity of the Mullen scales of early learning. American Journal of Intellectual and Developmental Disabilities (formerly American Journal of Mental Retardation) (in press).
3. Browne, M. W., & Cudeck, R. (1993). Alternative ways of assessing model fit. In K. A. Bollen & J. S. Long (Eds.), Testing structural equation models (pp. 136–162). Newbury Park, CA: Sage.
4. Chawarska, K., Paul, R., Klin, A., Hannigen, S., Dichtel, L., & Volkmar, F. (2007). Parental recognition of developmental problems in toddlers with autism spectrum disorders. Journal of Autism and Developmental Disorders, 38(1), 67–72.
5. Cronbach, L. J. (1951). Coefficient alpha and the internal structure of tests. Psychometrika, 16, 297–334.