एपीए उद्धरण

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

शिकागो स्टाइल उद्धरण

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

एमएलए उद्धरण

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