APA (7th ed.) Citation

Quirk, R., Greenbaum, S., Leech, G. N., & Svartvik, J. (1989). A grammar of contemporary English. Longman.

Chicago Style (17th ed.) Citation

Quirk, Randolph, Sidney Greenbaum, Geoffrey N. Leech, and Jan Svartvik. A Grammar of Contemporary English. Essex: Longman, 1989.

MLA (9th ed.) Citation

Quirk, Randolph, et al. A Grammar of Contemporary English. Longman, 1989.