BIBLIOGRAPHY

- Crystal, D., (2003), The Cambridge Encyclopaedia of Langauge. Cambridge University Press.- Hymes, D., (1972), On Communicative Competence, in: Sociolinguistics, Penguin.- Jakobson, R., (1995), On Language, MA: Harvard University Press.- Littlewood, W., (1981), Communicative Language Teaching. Cambridge University Press.