Cita APA (7a ed.)
de Blij, H. J., & Birdsall, S. (1974). Essential of geography: Regions and concets. John Wiley.
Cita Chicago Style (17a ed.)
de Blij, Harm J., y Stephen Birdsall. Essential of Geography: Regions and Concets. New York: John Wiley, 1974.
Cita MLA (9a ed.)
de Blij, Harm J., y Stephen Birdsall. Essential of Geography: Regions and Concets. John Wiley, 1974.
Precaución: Estas citas no son 100% exactas.