Dyfyniad APA

 Cunningham, W. P. (2012).  Environmental science: A global concern.  McGraw-Hill Companies, Inc.

Dyfyniad Arddull Chicago

 Cunningham, William P.  Environmental Science: A Global Concern.  McGraw-Hill Companies, Inc, 2012.

Dyfyniad MLA

 Cunningham, William P.  Environmental Science: A Global Concern.  McGraw-Hill Companies, Inc, 2012.

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