Dalzell, Robert S. <br/><br/>
Remedial and strata replacement technique on longwall faces 
Dalzell, Robert S. 
 - Washington  Bureau of mines  1985 
<br/><br/><label>Subjects--Topical Terms: </label><br/>MINERIA<br/>ESTRATIFICACION<br/>POZOS PROFUNDOS
<br/><br/><label>Universal Decimal Class. No.: </label>622:551.3.051.8