Cita APA (7a ed.)

Davidson, G., & Sten, G. (2005). A student's companion: Vocabulary and grammar. Learners Publishing.

Cita Chicago Style (17a ed.)

Davidson, George, y George Sten. A Student's Companion: Vocabulary and Grammar. Singapore: Learners Publishing, 2005.

Cita MLA (8a ed.)

Davidson, George, y George Sten. A Student's Companion: Vocabulary and Grammar. Learners Publishing, 2005.