APA aipamena

Wyatt, R., Duckworth, M., & Gude, K. (1999). Countdown to first certificate. Oxford: Oxford University Press.

Chicago Style aipamena

Wyatt, Rawdon., Michael Duckworth, và Kathy Gude. Countdown to First Certificate. Oxford: Oxford University Press, 1999.

MLA aipamena

Wyatt, Rawdon., Michael Duckworth, và Kathy Gude. Countdown to First Certificate. Oxford: Oxford University Press, 1999.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.