Cita APA

Thorpe, E., & Thorpe, S. (2012). Objective English (5th ed.). Pearson publishing.

Citación estilo Chicago

Thorpe, Edgar, y Showick Thorpe. Objective English. 5th ed. New Delhi: Pearson publishing, 2012.

Cita MLA

Thorpe, Edgar, y Showick Thorpe. Objective English. 5th ed. Pearson publishing, 2012.