Richards, J. C., Hull, J., & Proctor, S. (1996). Changes: English for international communication. Cambridge: Cambridge University Press.
Dyfyniad Arddull ChicagoRichards, Jack C., Jonathan Hull, và Susan Proctor. Changes: English for International Communication. Cambridge: Cambridge University Press, 1996.
Dyfyniad MLARichards, Jack C., Jonathan Hull, và Susan Proctor. Changes: English for International Communication. Cambridge: Cambridge University Press, 1996.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.