Dyfyniad APA

(1974). McGraw-Hill encyclopedia of environmental science. McGraw-Hill.

Dyfyniad Arddull Chicago

McGraw-Hill Encyclopedia of Environmental Science. New York: McGraw-Hill, 1974.

Dyfyniad MLA

McGraw-Hill Encyclopedia of Environmental Science. McGraw-Hill, 1974.

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