Richards, J. C. (1990). Interchange: English for international communication : Teacher's manual. New York, US: Cambridge University Press.
Παραπομπή Chicago StyleRichards, Jack C. Interchange: English for International Communication : Teacher's Manual. New York, US: Cambridge University Press, 1990.
Παραπομπή MLARichards, Jack C. Interchange: English for International Communication : Teacher's Manual. New York, US: Cambridge University Press, 1990.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.