THEOBALD, Paul K. <br/><br/>
The gold pan as a quantitative geologic tool / 
by Paul K. Theobald. 
 -- Washington :   United States Government Printing Office,   1957 
 - 54 p. -- 
 (Geological Survey Bulletin  ;  1071-A).
<br/><br/><label>Subjects--Topical Terms: </label><br/>Minerales<br/>Petrología
<br/><br/><label>Universal Decimal Class. No.: </label>552