prepared by the Wisconsin Geological and Natural History Survey and University of Wisconsin-Madison, Department of Geology and Geophysics, in conjunction with the North-Central Section, Geological Society of America meeting, held in Madison, Wisconsin, May 1-2, 1997
by G.N. Delin ... [and others] ; prepared in cooperation with the University of Minnesota Department of Soil Science, the U.S. Department of Agriculture, Agricultural Research Service, and the Minnesota Pollution Control Agency