1. Crystal, David The Cambridge Encyclopedia of Language . Cambridge University Press, 1997. Finocchiaro, Mary : English as a Second Language: from Theory to Practice . Regents Company Incorporated. USA. 1974. Gass, Susan Schachter . Linguistic Perspectives on Second Language Acquisition . Cambridge University Press, 1989. Hutchinson, Tom Water Alan . English for Special Purposes , Cambridge University Press, 1987. Krashen, Stephen D. Principles and Practice in Second Language Acquisition . Prentice-Hall International, 1987. Krashen, Stephen D. Second Language Acquisition and Second Language Learning . Prentice-Hall International, 1988. Krashen, Stephen . The Input Hypothesis: Issues and Implications . Longman, 1985. BIBLIOGRAPHY

2. Krashen Stephen, Terrell Tracy . The Natural Approach, Language acquisition in the classroom . Oxford University Press, 1988. Mackey, William Francis . Language Teaching Analysis . Longman, 1976. Richards, Jack & Renandya . Methodology in Language Teaching . Cambridge University Press, 2002. Richards Jack, Rodgers Theodore. Approaches and Methods in Language Teaching, a description and analysis . Cambridge University Press, 1986. Richards, Jack. Longman Dictionary of Applied Linguistics. Longman, 1985. Wallace, Michael. Training Foreign Language Teachers: a Reflective Approach . Cambridge University Press.