http://pec.lib.wvu.edu/record/P207531936Electrical viewpoint in a complete safety survey of a coal mine. <p> Serial issue. Issued as: United States. Bureau of Mines.<em> Information circular</em>, I. C. 6894 (1936:July).</p>Gleim, E. J. (Ernest J.)Mine safety.Coal mines and mining--Safety measures.14256