8Cho, K. S. & Krashen,S. D. Acquisition of Vocabulary from the Sweet Valley Kids Series: Adult ESL Acquisition[ J]. Journal of Reading, 1994.37(8) :662 - 667.
9Cho,K. S. & Krashen,S. D, Becoming a dragon: Progress in English as a Second Language through narrow Free Voluntary Reading[ J]. CaliforniaReader,1995,29(l ):9-10.
10Ellis,R. SLA Research and Language Teaching [ M] . Oxford;Oxford University Press, 1997.