House documents. 

 - Washington :  U.S.G.S.,  1910. 
 - 3 v. :  il. ;  23 cm 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geología económica<br/>Recurso minero
<br/><br/><label>Index Terms--Genre/Form: </label><br/>Libro
<br/><br/><label>Universal Decimal Class. No.: </label>553.3/.9