1996. Lively, R. S. and Morey, G.B. Maps showing general Quaternary age surface geology of Minnesota and distribution of uranium, thorium and potassium-40 in surface sediments, scale ... Minnesota Geological Survey.
1982. Chandler, Val W. Aeromagnetic anomaly (total magnetic intensity anomaly (relative to the earth's magnetic field, interpretation of magnetic data collected from airb... Minnesota Geological Survey.
1992. Chandler, Val W. Aeromagnetic anomaly (total magnetic intensity anomaly (relative to the earth's magnetic field, interpretation of magnetic data collected from airb... Minnesota Geological Survey.