Cita APA (7th ed.)

Azar, B. S., & Hagen, S. A. (2009). Understanding and using english grammar (4th ed.). Pearson.

Cita Chicago (17th ed.)

Azar, Betty S., i Stacy A. Hagen. Understanding and Using English Grammar. 4th ed. New York: Pearson, 2009.

Cita MLA (9th ed.)

Azar, Betty S., i Stacy A. Hagen. Understanding and Using English Grammar. 4th ed. Pearson, 2009.