1. Brocchi E. A. Jeffes J. H. E. ( 1985 ). Extraction Metallurgy'85 Symposium , 9–12 September , 1985 , IMM London , pp. 741 – 56 .
2. Moura F. J. Brocchi E. A. Kohler H. M. ( 1987 ). Pyrometallurgy'87, Symposium , 21–23 September , 1987 , IMM London , pp. 799 – 812 .