Dyfyniad APA

Soen, O. I. (1958). The geology, petrology and ore deposits of the Viseu region, northern Portugal .. Drukkerij Holland N. V..

Dyfyniad Arddull Chicago

Soen, Oen Ing. The Geology, Petrology and Ore Deposits of the Viseu Region, Northern Portugal .. Amsterdam: Drukkerij Holland N. V., 1958.

Dyfyniad MLA

Soen, Oen Ing. The Geology, Petrology and Ore Deposits of the Viseu Region, Northern Portugal .. Drukkerij Holland N. V., 1958.

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