Gaya APA

Azar, B, S., A.Hagen, S. (2009). Understanding and Using English Grammar with Answer Key . New York: Pearson Longman.

Gaya MLA

Azar, Betty, Schramfer., A.Hagen, Stacy. "Understanding and Using English Grammar with Answer Key". New York: Pearson Longman, 2009. textbook.