Dyfyniad APA

Wallen, R. N. (1992). Introduction to physical geography. WM C. Brown.

Dyfyniad Arddull Chicago

Wallen, Robert N. Introduction to Physical Geography. Boulevard: WM C. Brown, 1992.

Dyfyniad MLA

Wallen, Robert N. Introduction to Physical Geography. WM C. Brown, 1992.

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