Dyfyniad APA

International Union of Geological Society. (1993). Episodes,vol.16&17.

Dyfyniad Arddull Chicago

International Union of Geological Society. Episodes,vol.16&17. International Union of Geological Society, 1993.

Dyfyniad MLA

International Union of Geological Society. Episodes,vol.16&17. 1993.

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