9Brown, D. L. & R. A. Ferrara. Diagnosing zones of proximal development [ C] //P. Lloyd & C. Femyhough. LEV Vygotsky Critical Assessment. London and New York: Routledge, 1999, 3 : 225 - 253.
10Emig, J. The Composing Processes of Twelfth Graders [M]. Urbana, Ⅲ. : National Council of Teachers of English, 1971.
