APA استشهاد

Keller, E. A. (2011). Environmental geology (9th ed.). Prentice Hall.

استشهاد بنمط شيكاغو

Keller, Edward A. Environmental Geology. 9th ed. Boston: Prentice Hall, 2011.

MLA استشهاد

Keller, Edward A. Environmental Geology. 9th ed. Prentice Hall, 2011.