Ferguson, Henry G. <br/><br/>
Graphite in 1917. 

 - Washington, D.C.  Government Printing Office  1918 
 - pp. 97-119 
<br/><br/> Impreso 
<br/><br/><br/>Ingles 
<br/><br/><label>Subjects--Topical Terms: </label><br/>MINERIA