Hardwick, W.R. <br/><br/>
Open-Pit Copper Mining And Concentrating Methods And Costs, Silver Bell Unit, American Smelting And Refining Co., Pima County, Arizona 

 -  SEGEMARU.S.A.  1963 
<br/><br/> Departamento Del Interior De Los Estados Unidos, Circular 8153 
<br/><br/><label>Subjects--Index Terms: </label>Mineral/es: Cobre