http://pec.lib.wvu.edu/record/P194671946Storage of explosives in underground mines of the Lake Superior District.<p> Serial issue. Issued as: United States. Bureau of Mines. <em> Information circular,</em> 7343 (1946:Feb.).</p>Cash, Frank E. (Frank Errette)Iron mines and mining--Wisconsin.Iron mines and mining--Michigan.Mine explosives.Iron mines and mining--Minnesota.14256