Cita APA

Duckworth, M., & Gude, K. (1999). Countdown to first certificate: Student's book. Oxford: Oxford University Press.

Chicago Style Citation

Duckworth, Michael., i Kathy Gude. Countdown to First Certificate: Student's Book. Oxford: Oxford University Press, 1999.

Cita MLA

Duckworth, Michael., i Kathy Gude. Countdown to First Certificate: Student's Book. Oxford: Oxford University Press, 1999.