Cita APA

Duckworth, M., & Gude, K. (2000). Countdown to first certificate: Student's book (6th ed.). Oxford: Oxford U. P..

Chicago Style Citation

Duckworth, Michael, i Kathy Gude. Countdown to First Certificate: Student's Book. 6th ed. Oxford: Oxford U. P., 2000.

Cita MLA

Duckworth, Michael, i Kathy Gude. Countdown to First Certificate: Student's Book. 6th ed. Oxford: Oxford U. P., 2000.