MURPHY, T. D. <br/><br/>
Distribution of Silica resources in Eastern United States / 
by T. D. Murphy. 
 -- Washington :   United States Government Printing Office,   1960 
 - P. 657-665 + map. -- 
 (Geological Survey Bulletin  ;  1072-L).
<br/><br/><label>Subjects--Topical Terms: </label><br/>Estados Unidos<br/>Rocas silíceas
<br/><br/><label>Universal Decimal Class. No.: </label>552.55(73)