For Reading, zone theory

1. Valsiner, J. (1997). Culture and the development of children’s action: A theory of human development (2nd ed.). New York: John Wiley.
2. Vygotsky, L. S. (1962). Thought and language (E. Hanfmann & G. Vahar, Ed. & Trans.). Cambridge, MA: MIT Press. (Original work published 1934).