APA (7th ed.) Citation

Richards, J. C., Hull, J., & Protor, S. (1993). Interchange: English for international communication. Cambridge University.

Chicago Style (17th ed.) Citation

Richards, Jack C., Jonathan Hull, and Susan Protor. Interchange: English for International Communication. Cambridge University, 1993.

MLA (8th ed.) Citation

Richards, Jack C., et al. Interchange: English for International Communication. Cambridge University, 1993.