Cita APA (7th ed.)

Kingsbury, R. y. (1996). Grammar Plus 2 (1a. ed.). Longman.

Cita Chicago (17th ed.)

Kingsbury, Roy y. Grammar Plus 2. 1a. ed. Londres: Longman, 1996.

Cita MLA (9th ed.)

Kingsbury, Roy y. Grammar Plus 2. 1a. ed. Longman, 1996.