Richards, J. C. (1994). Changes: English for international communication. Cambridge: Cambridge University Press.
Dyfyniad Arddull ChicagoRichards, Jack C. Changes: English for International Communication. Cambridge: Cambridge University Press, 1994.
Dyfyniad MLARichards, Jack C. Changes: English for International Communication. Cambridge: Cambridge University Press, 1994.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.