Dyfyniad APA

Frehner. Finding Oil. University of Nebraska Press.

Dyfyniad Arddull Chicago

Frehner. Finding Oil. University of Nebraska Press.

Dyfyniad MLA

Frehner. Finding Oil. University of Nebraska Press.

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