Dyfyniad APA

Watt, K. F. (1973). Principles of environmental science. McGraw-Hill.

Dyfyniad Arddull Chicago

Watt, Kenneth F. Principles of Environmental Science. New York: McGraw-Hill, 1973.

Dyfyniad MLA

Watt, Kenneth F. Principles of Environmental Science. McGraw-Hill, 1973.

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