Cita APA (7a ed.)

Swan, M. (2005). Practical english usage (3ª ed.). Oxford University.

Cita Chicago Style (17a ed.)

Swan, Michael. Practical English Usage. 3ª ed. Oxford: Oxford University, 2005.

Cita MLA (9a ed.)

Swan, Michael. Practical English Usage. 3ª ed. Oxford University, 2005.