Effect of ultralow frequency signaling on blasting array current / 
by Kenneth E. Hjelmstad and Russell E. Griffin. 
 - Avondale, Md. :  U.S. Dept. of the Interior, Bureau of Mines,  1993. 
 - 7 p. 
 - Report of investigations ;  9479 .
 - Report of investigations (United States. Bureau of Mines) ;  9479 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mines and mineral resources.<br/>Electric detonators--Safety measures.<br/>Electromagnetic waves--Transmission.<br/>Fire alarms.