1. 1) G. A. J. Hack: Powder Met., 27 (1984), 73.
2. 2) P. K. Ghosh and S. Ray: Z. Metallk., 80 (1989), 53.
3. 3) T. Choh, J. Ebihara and T. Oki: J. Japan Inst. Light Metals, 38 (1988), 600.
4. 4) Infusible Compounds, L. F. Voidvich, Nissotushinsha, (1971), p. 67.
5. 5) Thermochemistry for steelmaking, J. F. Elliott, M. Gleiser and V. Ramakrishna, 1 (1963), p. 147. Addison-Weslei Pub. Co. Inc.