Click on the following links. Please note these will open in a new window.

A good overview of the development of play in infants and children:
Casby, M. W. (2003). The development of play in infants, toddlers, and young children. Communication Disorders Quarterly, 24(4), 163-174

A cross-cultural study of pretend play:
Chessa, D., Lis, A., Di Riso, D., Delvecchio, E., Mazzeschi, C., Russ, S.W., & Dillon, J. (2012). A cross-cultural comparison of pretend play in U.S. and Italian children. Journal of Cross-Cultural Psychology, 44(4): 640-656.