1. 1) J. M. Gray, S. V. Subramanian and D. A. R. Kay: HSLA Steels Technology & Application, ASM, (1984), p. 967.
2. 2) R. Langeborg, O. Sandberg and W. Roberts: Fundamental of Microalloying Forging Steels, ed. by G. Krauss and S. K. Banerji, TMS AIME, (1987), p. 39.
3. 3) M. Katsumata, O. Matsumoto, Y. Kanetsuki, T. Inoue, M. Nakamura, Y. Matsushima and Y. Nakatani: Proceedings on International Conference on Mortar Vehicle Manufacture, Stahl Eisen, (1990), p. 243.
4. 4) W. Steven and A. G. Haynes: J. Iron Steel Inst., 183 (1956), 349.
5. 5) S. W. Thompson, D. J. Colvin and G. Krauss: Metall. Trans. A, 21A (1990), 1493.