1. , , , and The Emergence of Symbols. Orlando, Fla.: Academic, 1979.
2. , , and Social Bases of Language Development: A Reassessment. In and (eds.), Advances in Child Development and Behavior. Vol. 16. Orlando, Fla.: Academic, 1982.
3. and The Cognitive Hypothesis in Language Development. In and (eds.), Research with Scales of Psychological Development in Infancy. Urbana: University of Illinois Press, 1987.
4. Bayley Scales of Infant Development. New York: Psychological Corporation, 1969.
5. and “Development of Functional Communication During Stage 1 of Syntactic Development by Children with Down's Syndrome.” Presented at the tenth annual Boston University Conference on Language Development, Boston, Mass., October 1985.