Richards, J. C., Hull, J., & Proctor, S. (1995). Changes: English for international communication. Cambridge: Cambridge University Press.
Παραπομπή Chicago StyleRichards, Jack C., Jonathan Hull, και Susan Proctor. Changes: English for International Communication. Cambridge: Cambridge University Press, 1995.
Παραπομπή MLARichards, Jack C., Jonathan Hull, και Susan Proctor. Changes: English for International Communication. Cambridge: Cambridge University Press, 1995.
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