Dyfyniad APA

Don Leet,L, & Judson, S. (1969). Physical geology (3rd ed.). Prentice hall.

Dyfyniad Arddull Chicago

Don Leet,L, and Sheldon Judson. Physical Geology. 3rd ed. New delhi: Prentice hall, 1969.

Dyfyniad MLA

Don Leet,L, and Sheldon Judson. Physical Geology. 3rd ed. Prentice hall, 1969.

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