4[1]Krahnke, K, J. (1987). Approaches to syllabus design for foreign language teaching. New Jersey: Prentice- Hall, Inc.
5[2]Krashen, S. (1985). The input hypothesis: Issues and implications. New York: Longman.
6[3]Leaver, B. L., & Stryker, S. B. (1989). Content-based instruction for foreign language classrooms. Foreign Language Annals.
7[4]Brinton, D., Snow, M. and Wesche, M. (1989). Contentbased second language instruction. New York: Newbury House.
8[5]Anderson, J. (1990). Cognitive psychology and its implications (3rd ed.). New York: W. H. Freeman.
9[6]Bereiter, C., and Scardmalia, M. (1993). Surpassing ourselves: An inquiry into the nature And implications of expertise.Chicago: Open Court Press.
10[7]Stoller, F, and Grabe, W. (1997). A six- T's approach to content- based instruction. In the content- based classroom:Perspectives on integrating language and content. eds. Snow, M and Brinton, D. White Plains. NY: Longman.