Lesher, C. E. <br/><br/>
Coal in 1918. Part A. Production. 

 - Washington, D.C.  Government Printing Office  1920 
 - pp. 695-813 
 - Mineral Resources of the United States, 1918-Part II .
<br/><br/> Impreso 
<br/><br/><br/>Ingles 
<br/><br/><label>Subjects--Topical Terms: </label><br/>MINERIA<br/>CARBON
<br/><br/><label>Subjects--Index Terms: </label>PRODUCCION DE CARBON 
<br/><br/><label>Dewey Class. No.: </label>553.2