1. Japan Society of Mechanical Engineers (1982) Design Handbook of Fatigue Strength of Metals, Vol. 1, p. 125 (see Appendix 3), Tokyo
2. Photographs of Metal Structure - Steels;Nisizawa,1979
3. Nippon Steel Corporation (1970) Technical data
4. Introduction to Linear Fracture Mechanics;Okamura,1976
5. Fractography;Kitagawa,1977