एपीए उद्धरण

Michael Duckworth. (1999). Countdown to first certificate ( Teacher's book ). Oxford: Oxford Univ. Press.

शिकागो स्टाइल उद्धरण

Michael Duckworth. Countdown to First Certificate ( Teacher's Book ). Oxford: Oxford Univ. Press, 1999.

एमएलए उद्धरण

Michael Duckworth. Countdown to First Certificate ( Teacher's Book ). Oxford: Oxford Univ. Press, 1999.