Não informado. (2001). Bulletin of the Wisconsin Geological and Natural History Survey. Wisconsin Geological and Natural History Survey.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Bulletin of the Wisconsin Geological and Natural History Survey. Madison, Wis: Wisconsin Geological and Natural History Survey, 2001.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Bulletin of the Wisconsin Geological and Natural History Survey. Wisconsin Geological and Natural History Survey, 2001.
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