1. J.R. Boldt, Jr., “The Winning of Nickel” (Toronto: Longmans Canada Ltd., 1967), pp. 299–314.
2. J.S. Mitchell, JOM, 9(3) (1957), pp. 343–345.
3. E.T. Carlson and C.S. Simons, Extractive Metallurgy of Copper, Nickel and Cobalt, ed. P. Queneau (New York: AIME, 1961), pp. 363–396.
4. R.P. Plasket and S. Romanchuk, Hydrometallurgy, 3 (1978), pp. 135–151.
5. E.G. Parker, CIM Bull., 74 (May 1981), pp. 145–150.