Dyfyniad APA

Cunningham, W. P., & Cunningham, M. A. (2012). Environmental science: A global concern (12th ed.). McGraw-Hill Companies, Inc.

Dyfyniad Arddull Chicago

Cunningham, William P., and Mary Ann Cunningham. Environmental Science: A Global Concern. 12th ed. New York: McGraw-Hill Companies, Inc, 2012.

Dyfyniad MLA

Cunningham, William P., and Mary Ann Cunningham. Environmental Science: A Global Concern. 12th ed. McGraw-Hill Companies, Inc, 2012.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.