Lowrie, Raymond L. <br/><br/>
Underground mines 
Lowrie, Raymond L. 
 - Washington  Bureau of Mines  1968 
 - 19 p.  il 
 - RI  7109 Recovery percentage of bituminous coal deposits in the United States  1 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>underground mining<br/>bituminous coal<br/>recovery
<br/><br/><label>Subjects--Geographic Terms: </label><br/>United States
<br/><br/><label>Universal Decimal Class. No.: </label>55