Hewlett, Richard F. <br/><br/>
Comparison of the triangular, polygonal, and a statistical method of computing grade and tonnage of ore for the Silver Bell Oxide porphyry copper deposit 
Richard F. Hewlett 
 - Washington  Bureau of Mines  1970 
 - ii, 33 p.  il., maps  26 cm 
 - RI  7331 .
<br/><br/> Based on work done in cooperation with the Bear Creek Mining Co., and on a fellowship agreement with the College of Mines, University of Arizona. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>copper ores<br/>classification
<br/><br/><label>Subjects--Index Terms: </label>grading 
<br/><br/><label>Universal Decimal Class. No.: </label>552