Cita APA (7a ed.)

McGrath, I., & Prowse, P. (1993). Intermediate Grammar Helpline. Heinemann.

Cita Chicago Style (17a ed.)

McGrath, Ian, y Philip Prowse. Intermediate Grammar Helpline. Oxford: Heinemann, 1993.

Cita MLA (8a ed.)

McGrath, Ian, y Philip Prowse. Intermediate Grammar Helpline. Heinemann, 1993.