APA (7th ed.) Zitazioa
de Blij, H. J., & Birdsall, S. (1988). Essential of geography: Regions and concets (5th ed.). John Wiley.
Chicago Style (17th ed.) Zitazioa
de Blij, Harm J., eta Stephen Birdsall. Essential of Geography: Regions and Concets. 5th ed. New York: John Wiley, 1988.
MLA (9th ed.) Zitazioa
de Blij, Harm J., eta Stephen Birdsall. Essential of Geography: Regions and Concets. 5th ed. John Wiley, 1988.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.