Geological features that contribute to ground control problems in underground coal mines / 
by Valois R. Shea-Albin. 
 - Avondale, Md. :  U.S. Dept. of the Interior, Bureau of Mines,  1993. 
 - 38 p. 
 - Information circular ;  9370 .
 - Information circular (United States. Bureau of Mines) ;  9370 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mines and mineral resources.<br/>Ground control (Mining).<br/>Coal--Geology