Cita APA (7a ed.)

Swan, M. (1990). Practical English usage (19th impr.). Oxford University Press.

Cita Chicago Style (17a ed.)

Swan, Michael. Practical English Usage. 19th impr. Oxford: Oxford University Press, 1990.

Cita MLA (9a ed.)

Swan, Michael. Practical English Usage. 19th impr. Oxford University Press, 1990.