Dyfyniad APA

International Union of Geological Society. (1987). Episodes,vol.10&11.

Dyfyniad Arddull Chicago

International Union of Geological Society. Episodes,vol.10&11. International Union of Geological Society, 1987.

Dyfyniad MLA

International Union of Geological Society. Episodes,vol.10&11. 1987.

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