Gaya APA

Azar, B, S., Hagen, S, A. (2009). Understanding and using English grammar: with answer key. Fourth Edition (dilengkapi CD) (Ed.Ke-4). : Pearson Education.

Gaya MLA

Azar, Betty, S.., Hagen, Stacy, A.. "Understanding and using English grammar: with answer key. Fourth Edition (dilengkapi CD)". Ed.Ke-4 : Pearson Education, 2009. Textbook.