एपीए उद्धरण

(2006). Cambridge exams extra PET with answers. Cambridge, UK: Cambidge University Press.

शिकागो स्टाइल उद्धरण

Cambridge Exams Extra PET With Answers. Cambridge, UK: Cambidge University Press, 2006.

एमएलए उद्धरण

Cambridge Exams Extra PET With Answers. Cambridge, UK: Cambidge University Press, 2006.