Não informado. Studies in Geography. Northwestern University, Department of Geography.
Citação do estilo Chicago (17ª ed.)Não informado. Studies in Geography. Evanston, Ill: Northwestern University, Department of Geography.
Citação MLA (8ª ed.)Não informado. Studies in Geography. Northwestern University, Department of Geography.
Atenció: Aquestes cites poden no estar 100% correctes.