Cita APA (7th ed.)

May P. Peter. (2009). Knockout. First Certificate: Student's book. Oxford, Oxford University Press, 2009.

Cita Chicago (17th ed.)

May P. Peter. Knockout. First Certificate: Student's Book. Oxford, Oxford University Press, 2009, 2009.

Cita MLA (9th ed.)

May P. Peter. Knockout. First Certificate: Student's Book. Oxford, Oxford University Press, 2009, 2009.