1. 1) K. Born : Stahl Eisen, 73 (1953), 1268.
2. 2) A. Nicholson and J. D. Murray : J. Iron Steel Inst., 203 (1965), 1007.
3. 3) I. L. May and L. M. Schetky : Copper in Iron and Steel, John Wiley & Sons, Inc., New York, (1982).
4. 5) K. Noro, M. Takeuchi and Y. Mizukami : ISIJ Int., 37 (1997), 198.
5. 6) H. Yamauch, M. Miwa and H. Kobayasi : Bull. Iron Steel Inst. Jpn., 4 (1995), 378.