Παραπομπή APA

Swan,, M. (1996). Practical English usage (2nd ed.). OUP.

Παραπομπή Chicago Style

Swan,, Michael. Practical English Usage. 2nd ed. Oxford: OUP, 1996.

Παραπομπή MLA

Swan,, Michael. Practical English Usage. 2nd ed. OUP, 1996.