Dutch, Steve, Professor of Natural and Applied Sciences, University of Wisconsin-Green Bay. "Pleistocene Glaciers and Geography" webpage [Архівовано 6 лютого 2014 у Wayback Machine.] (accessed 11/30/2006)
web.archive.org
Dutch, Steve, Professor of Natural and Applied Sciences, University of Wisconsin-Green Bay. "Pleistocene Glaciers and Geography" webpage [Архівовано 6 лютого 2014 у Wayback Machine.] (accessed 11/30/2006)
