APA (7th ed.) Zitazioa

Swan, M. (2006). Practical English usage. Oxford U. pr.

Chicago Style (17th ed.) Zitazioa

Swan, Michael. Practical English Usage. New Delhi: Oxford U. pr, 2006.

MLA (9th ed.) Zitazioa

Swan, Michael. Practical English Usage. Oxford U. pr, 2006.