1. Dunn, J.F. & Dale, N. (1984). I a daddy: two-year-olds' collaboration in joint pretend with sibling and with mother. In I. Bretherton (ed.), Symbolic Play: The Development of Social Understanding ( New York: Academic Press), 131-158.
2. The Language of Children Reared in Poverty: Implication for Evaluation and Intervention;Feagans, L.,1982