एपीए उद्धरण

Duff, P. (1993). Holmes'principles of Physical Geology, 4th ed. Chapman &Hall.

शिकागो स्टाइल उद्धरण

Duff, P.McL.D. Holmes'principles of Physical Geology, 4th Ed. London: Chapman &Hall, 1993.

एमएलए उद्धरण

Duff, P.McL.D. Holmes'principles of Physical Geology, 4th Ed. Chapman &Hall, 1993.