Não informado. (2009). Occasional Publications of the Department of Geography. University of Illinois at Urbana-Champaign.
Citação do estilo Chicago (17ª ed.)Não informado. Occasional Publications of the Department of Geography. Urbana, Ill: University of Illinois at Urbana-Champaign, 2009.
Citação MLA (8ª ed.)Não informado. Occasional Publications of the Department of Geography. University of Illinois at Urbana-Champaign, 2009.
Atenció: Aquestes cites poden no estar 100% correctes.