Summers, Charles R. <br/><br/>
Noise abatement of pneumatic rock drill 
Summers, Charles R.; Murphy, John N. 
 - Washington  Bureau of mines  1974 
 - 45 p. 
 - RI 7998 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>MINERIA<br/>MINING
<br/><br/><label>Subjects--Index Terms: </label>MINAS DE CARBON MAQUINARIA NEUMATICA TALADRO DE ROCAS COAL MINES PNEUMATIC MACHINERY ROCK-DRILLS 
<br/><br/><label>Universal Decimal Class. No.: </label>622