Richards, J. C., Hull, J., & Proctor, S. (1994). Changes: English for international communication : student's book 1. Cambridge: Cambridge University Press.
Trích dẫn kiểu ChicagoRichards, Jack C., Jonathan Hull, và Susan Proctor. Changes: English for International Communication : Student's Book 1. Cambridge: Cambridge University Press, 1994.
MLA引文Richards, Jack C., Jonathan Hull, và Susan Proctor. Changes: English for International Communication : Student's Book 1. Cambridge: Cambridge University Press, 1994.
警告：這些引文格式不一定是100％准確.