APA (7th ed.) Citation

Greenbaum, S. (1991). An introduction to English grammar / Sidney Greenbaum. Longman.

Chicago Style (17th ed.) Citation

Greenbaum, Sidney. An Introduction to English Grammar / Sidney Greenbaum. Harlow: Longman, 1991.

MLA (9th ed.) Citation

Greenbaum, Sidney. An Introduction to English Grammar / Sidney Greenbaum. Longman, 1991.

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