Mineral facts and problems 

 - Washington, D. C. :  United States Government Printing Office,  1956 
 - 1042 p. :  ill. ;  25 cm. 
 - Bureau of mines ;  bulletin 556 .
<br/><br/>Includes bibliographies. p. 1003 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mines and mineral resources--United States<br/>Mineral industries--United States