एपीए उद्धरण

Duff, P. M. D. (1992). Holmes' Principles of physical geology (4th ed.). ELBS with chapman & hall.

शिकागो स्टाइल उद्धरण

Duff, P Mcl D. Holmes' Principles of Physical Geology. 4th ed. London: ELBS with chapman & hall, 1992.

एमएलए उद्धरण

Duff, P Mcl D. Holmes' Principles of Physical Geology. 4th ed. ELBS with chapman & hall, 1992.