APA (7th ed.) Zitazioa

Birdsall, S. S. (1992). Outline of American geography: Regional landscapes of the united States (4th ed.). John Willey.

Chicago Style (17th ed.) Zitazioa

Birdsall, Stephen S. Outline of American Geography: Regional Landscapes of the United States. 4th ed. California: John Willey, 1992.

MLA (9th ed.) Zitazioa

Birdsall, Stephen S. Outline of American Geography: Regional Landscapes of the United States. 4th ed. John Willey, 1992.