1. 1) A. R. Burkin: Extractive Metallurgy of Nickel, Society of Chemical Industry, John Wiley & Sons, Great Britain, (1987), p. 9.
2. 2) R. S. Celmer and J. M. Toguri: Proc. of the Terkel Rosenquist Symposium, the Norwegian Institute of Technology, Trondheim, (1988), p. 341.
3. 3) N. Choi and W. D. Cho: Metall. Trans., 28B (1997), 429.
4. 4) G. Roghani, M. Hino and K. Itagaki: Proc. of the 5th. Intern. Conf. on the Molten Slags, Fluxes and Slags ’97, ISS, Sidney, (1997), p. 693.
5. 5) J. M. Font, Y. Takeda and K. Itagaki: Mater. Trans. JIM, 39 (1998), 652.