APA-viite (7. p.)

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

Chicago-viite (17. p.)

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

MLA-viite (9. p.)

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