Dyfyniad APA

Spencer, E. W. Basic concepts of historical geology.

Dyfyniad Arddull Chicago

Spencer, Edgar Winston. Basic Concepts of Historical Geology.

Dyfyniad MLA

Spencer, Edgar Winston. Basic Concepts of Historical Geology.

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