Mgbasa ozi ọla kọpa

akara 1870, enweela ọtụtụ mbọ iji ike ihie iko, n'ụdị a, ọnụ ya.

Nke a bụ ndepụta nke cartel ọla kọpa na awụ nke 20:

 Njikọ Mbupụ ọla kọpa, CEA, 1918–1923
 Ndị na-ebupụ ọla kọpa, Inc., CEI, 1926–1932
 International Copper Cartel, ICC, 1935 – 1939 (nke World Copper Agreement mebere)
 Kansụl gọọmentị etiti nke mba ndị na-ebupụ ọla kọpa, CIPEC, 1967–1988

 Ọgụgụ ọzọ 


 Herfindahl, O. (1959) Ọnụ ego ọla kọpa na ọnụ ahịa: 1870-1957, RFF, Baltimore.
Òtù:Ikike Nri