(1959). Vol. 54, № 4-5; Economic Geology. 1959.
Dyfyniad Arddull ChicagoVol. 54, № 4-5; Economic Geology. 1959, 1959.
Dyfyniad MLAVol. 54, № 4-5; Economic Geology. 1959, 1959.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.
(1959). Vol. 54, № 4-5; Economic Geology. 1959.
Dyfyniad Arddull ChicagoVol. 54, № 4-5; Economic Geology. 1959, 1959.
Dyfyniad MLAVol. 54, № 4-5; Economic Geology. 1959, 1959.