Cita APA (7th ed.)

Swan, M. (2003). Practical English usage (Fifth impression.). Oxford University Press.

Cita Chicago (17th ed.)

Swan, Michael. Practical English Usage. Fifth impression. Oxford ; New York: Oxford University Press, 2003.

Cita MLA (8th ed.)

Swan, Michael. Practical English Usage. Fifth impression. Oxford University Press, 2003.