Παραπομπή APA

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

Παραπομπή Chicago Style

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

Παραπομπή MLA

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