Wells, Roger Clark,  1877-1944. <br/><br/>
The Fractional precipitation of some ore-forming compounds at moderate temperatures / 
by Roger C. Wells. 
 - Washington,  Govt. Print. Off.,  1915. 
 - 46 p. :  diagrs. ;  24 cm. 
 - U.S. Geological survey. Bulletin 609 .
 - United States.  Geological Survey.  Bulletin ;  609. .
<br/><br/><label>LCCN: </label>gs 15000806  
<br/><br/><label>LC Class. No.: </label>TN263  / .W45