Cita APA (7a ed.)

Downing, A., & Locke, P. (1995). A university course in English grammar. Phoenix ELT.

Cita Chicago Style (17a ed.)

Downing, Angela, y Philip Locke. A University Course in English Grammar. New York [etc.]: Phoenix ELT, 1995.

Cita MLA (9a ed.)

Downing, Angela, y Philip Locke. A University Course in English Grammar. Phoenix ELT, 1995.