Cita APA

Duckworth, M. (2009). Countdown to first certificate: (Student's book). Oxford: Oxford University Press.

Citación estilo Chicago

Duckworth, Michael. Countdown to First Certificate: (Student's Book). Oxford: Oxford University Press, 2009.

Cita MLA

Duckworth, Michael. Countdown to First Certificate: (Student's Book). Oxford: Oxford University Press, 2009.