Kerr, George L., <br/><br/>
Elementary coal-mining :  Designed to meet the requirements of students attending classes on coal-mining, and of miners and others engaged in practical work / 
By George l. kerr 
 - 225 páginas 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Minas de carbón
<br/><br/><label>LC Class. No.: </label>TN802  / K47