Dyfyniad APA

(1976). International Union of geological science. John Wiley.

Dyfyniad Arddull Chicago

International Union of Geological Science. New York: John Wiley, 1976.

Dyfyniad MLA

International Union of Geological Science. John Wiley, 1976.

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