Cita APA (7th ed.)

Swan, M. (1995). Practical english usage (2a. ed.). Oxford University Press.

Cita Chicago (17th ed.)

Swan, Michael. Practical English Usage. 2a. ed. Oxford: Oxford University Press, 1995.

Cita MLA (9th ed.)

Swan, Michael. Practical English Usage. 2a. ed. Oxford University Press, 1995.