Cita APA (7a ed.)

Clarke, W., & Mackenzie, M. M. (1973). Modern english practice. Longman.

Cita Chicago Style (17a ed.)

Clarke, Waldo, y M.D. Munro Mackenzie. Modern English Practice. Harlow: Longman, 1973.

Cita MLA (9a ed.)

Clarke, Waldo, y M.D. Munro Mackenzie. Modern English Practice. Longman, 1973.