APA (7th ed.) Citation

Azar B. S. Betty Schrampfer & Hagen S. A. Stacy. (2009). Understanding and using English grammar with answer key (4th ed.). New York, Longman, 2009.

Chicago Style (17th ed.) Citation

Azar B. S. Betty Schrampfer and Hagen S. A. Stacy. Understanding and Using English Grammar with Answer Key. 4th ed. New York, Longman, 2009, 2009.

MLA (9th ed.) Citation

Azar B. S. Betty Schrampfer and Hagen S. A. Stacy. Understanding and Using English Grammar with Answer Key. 4th ed. New York, Longman, 2009, 2009.