1. G. Bridgstock, E. M. Elkin, and S. S. Forbes: Can. Min. Met. Bull., 1960, pp. 773–87.
2. P. Stables and L. R. Verney: Development in Tankhouse Operations at Ndola Copper Refiners, Zambia, XXXVI International Congress on Industrial Chemistry, Brussels, September, 1966.
3. L. L. Shreir and J. W. Smith: Faraday Soc. Trans., 1954, vol. 50, p. 393.
4. J. O'M. Bockris and A. K. N. Reddy: Modern Electrochemistry, vol. II, Section 10.2, Plenum, New York, 1973.
5. C. W. Eichrodt and J. H. Schloen: Copper, A. Butts, ed., Reinhold Publishing Corp., New York, 1960.