TY  - SER
AU  - Wlliams, Robert.
TI  - Progress and working costs, Tangayika Cooper Mines
T2  - Mining press ; 
PY  - 1914///
CY  - San Francisco-XXU : 
PB  - The Scientific Press, 
KW  - MINERALES
KW  - PRODUCCION MINERA
KW  - MINERIA
N1  - Contiene: Comaparison with the rand.- Cost of Cooper Production.- Progress at the mines
ER  -