1. 1) S. Taniguchi and A. Kikuchi: Tetsu-to-Hagané, 78(1992), 527.
2. 2) JSPS: 19th Committee: Recent Investigations on Non-metallic Inclusions in Molten Steel, JSPS, Tokyo, (1994).
3. 3) J. Yoshida, M. Iguchi and S. Yokoya: Tetsu-to-Hagané, 87(2001), No.8, 529.
4. 4) S. Asai: 100th and 101st Nishiyama Memorial Seminar, ISIJ, Tokyo, (1984), 65.
5. 5) M. Iguchi, J. Yoshida, T. Shimizu and Y. Mizuno: ISIJ Int., 40(2000), 685.