एपीए उद्धरण

Purkis, J. (1973). Open university: Where angels fear to tread. Open University Press.

शिकागो स्टाइल उद्धरण

Purkis, John. Open University: Where Angels Fear to Tread. Milton Keynes: Open University Press, 1973.

एमएलए उद्धरण

Purkis, John. Open University: Where Angels Fear to Tread. Open University Press, 1973.