1. Hart, N. W. M., Walker, R. F. and Gray, B. 1977.The Language of Children: A Key to Literacy, 1Reading, Mass.: Addison‐Wesley.
2. 1977.Report of the Urbana Conference on Competence in English, 8Urbana: University of Illinois Curriculum Laboratory.
3. Social Functions of Children s Speech
4. Connolly, Kevin J. and Bruner, Jerome S. 1974.The Growth of Competence, 3–7. New York: Academic Press.