May, P. (1999). Knockout first certificate: Student's book (5th ed.). Oxford: Oxford University Press.
Παραπομπή Chicago StyleMay, Peter. Knockout First Certificate: Student's Book. 5th ed. Oxford: Oxford University Press, 1999.
Παραπομπή MLAMay, Peter. Knockout First Certificate: Student's Book. 5th ed. Oxford: Oxford University Press, 1999.
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