Dyfyniad APA

Levorsen, A. I. (1967). Geology of petroleum (2nd ed.). Feffer and Simons.

Dyfyniad Arddull Chicago

Levorsen, A. I. Geology of Petroleum. 2nd ed. Bombay: Feffer and Simons, 1967.

Dyfyniad MLA

Levorsen, A. I. Geology of Petroleum. 2nd ed. Feffer and Simons, 1967.

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