McCulloch, Charles M. <br/><br/>
Geologic investigations of underground coal mining problems 
McCulloch, Charles M.; Jeran, P. W.; Sullivan, C. D. 
 - Washington  Bureau of mines  1975 
 - 30 p. 
 - RI 8022 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>GEOLOGIA<br/>GEOLOGY
<br/><br/><label>Subjects--Index Terms: </label>MINERIA SUBTERRANEA DE CARBON UNDERGROUND COAL MINING 
<br/><br/><label>Universal Decimal Class. No.: </label>55