Não informado. (1972). Geographical survey. Ball State University, Department of Geography and Geology.
Chicago-Zitierstil (17. Ausg.)Não informado. Geographical Survey. Muncie, Ind: Ball State University, Department of Geography and Geology, 1972.
MLA-Zitierstil (8. Ausg.)Não informado. Geographical Survey. Ball State University, Department of Geography and Geology, 1972.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.