Sinha, R. K. <br/><br/>
Mineral economics / 
R. K. Sinha and N. L. Sharma 
 - 2nd ed. 
 - New Delhi :  Oxford and IBH Pub. Co.,  1976 
 - vi, 368 p. :  ill. ;  22 cm. 
<br/><br/>p. 351-357 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mines and mineral resources<br/>Mineral industries--Study and teaching