एपीए उद्धरण

Ruth Gairns. (2003). Natural english (upper- intermediate student's book). Oxford, NY: Oxford Univ. Press.

शिकागो स्टाइल उद्धरण

Ruth Gairns. Natural English (upper- Intermediate Student's Book). Oxford, NY: Oxford Univ. Press, 2003.

एमएलए उद्धरण

Ruth Gairns. Natural English (upper- Intermediate Student's Book). Oxford, NY: Oxford Univ. Press, 2003.