Gaya APA

Hagen, B, S, A, S, A. (2013). Understanding and Using English Grammar Etext with Audio; Without Answer Key (Access Card) . : Allyn & Bacon.

Gaya MLA

Hagen, Betty, S., Azar;, Stacy, A.. "Understanding and Using English Grammar Etext with Audio; Without Answer Key (Access Card)". : Allyn & Bacon, 2013. Text.