1. 1) F.A.Stephens, J.P.Hager and F.M.Stephens, Jr. : U.S.Patent 5,073, 194, December, (1991)
2. 2) G.H.Geiger and F.A.Stephens : Ironmaking Conf. Proc., (1993), 333.
3. 12) F.Gronvold and A.Sveen : J.Chem. Thermodyn., 6 (1974), 859.
4. 13) F.Gronvold and E.J.Samuelsen : J.Phys. Chem. Solids, 36 (1975), 249.
5. 14) J.F.Elliott and M.Gleiser : Thermochemistry for Steelmaking, Vol.1, Addition Wesley, (1960)