1. 1) C. H. Luiten, F. Limque and F. Bless: Härterei Tech. Mitt., 34 (1979), 253.
2. 2) Metals Handbook, 9th Ed., Vol. 2, American Society for Metals, Metals Park, (1981), p. 270.
3. 3) R. C. Fisher: Härterei Tech. Mitt., 37 (1982), 220.
4. 4) W. J. Doelker: Metal Progr., 111 (1977), 50.
5. 5) K. Okamoto, M. Tominaga, H. Ono and Y. Nishiyama: J. Japan Inst. Metals, 46 (1982), 827 (in Japanese).