APA (7th ed.) Citation

Richards, Hull, & Proctor. (1990). Interchange: English for international communication. Cambridge Uni.

Chicago Style (17th ed.) Citation

Richards, Hull, and Proctor. Interchange: English for International Communication. London: Cambridge Uni, 1990.

MLA (8th ed.) Citation

Richards, et al. Interchange: English for International Communication. Cambridge Uni, 1990.

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