Não informado. (1972). Geographical survey. Ball State University, Department of Geography and Geology.
Style de citation Chicago (17e éd.)Não informado. Geographical Survey. Muncie, Ind: Ball State University, Department of Geography and Geology, 1972.
Style de citation MLA (8e éd.)Não informado. Geographical Survey. Ball State University, Department of Geography and Geology, 1972.
Attention : ces citations peuvent ne pas être correctes à 100%.