Não informado. (1972). Geographical survey. Ball State University, Department of Geography and Geology.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Geographical Survey. Muncie, Ind: Ball State University, Department of Geography and Geology, 1972.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Geographical Survey. Ball State University, Department of Geography and Geology, 1972.
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