APA (7th ed.) Citation

Greenbaum, S. (1996). An introduction to English grammar. Longman.

Chicago Style (17th ed.) Citation

Greenbaum, Sidney. An Introduction to English Grammar. Harlow, Essex, Eng: Longman, 1996.

MLA (9th ed.) Citation

Greenbaum, Sidney. An Introduction to English Grammar. Longman, 1996.