Não informado. Studies in Geography. Northwestern University, Department of Geography.
Chicago-Zitierstil (17. Ausg.)Não informado. Studies in Geography. Evanston, Ill: Northwestern University, Department of Geography.
MLA-Zitierstil (8. Ausg.)Não informado. Studies in Geography. Northwestern University, Department of Geography.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.