APA (7th ed.) Citation

Richards, Proctor, & Hull. (1991). Interchange: English for international communication. Cambridge Uni.

Chicago Style (17th ed.) Citation

Richards, Proctor, and Hull. Interchange: English for International Communication. London: Cambridge Uni, 1991.

MLA (8th ed.) Citation

Richards, et al. Interchange: English for International Communication. Cambridge Uni, 1991.

Warning: These citations may not always be 100% accurate.