Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

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

Cita MLA (8th ed.)

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