1. 1) International Organization for Standardization (ISO), Unified method of test for the determination of quasistatic fracture toughness, ISO12135 (2002).
2. 2) International Organization for Standardization, Method of test for the determination of quasistatic fracture toughness of welds, ISO15653 (2010).
3. 3) British Standards Institution, "Methods for crack opening displacement testing -COD- DD19," 1972.
4. 4) American Society for Testing and Materials (ASTM), "Standard test method for crack-tip opening displacement (CTOD) fracture toughness measurement," ASTM E1290.
5. 5) T. Kawabata, T. Tagawa, T. Sakimoto, Y. Kayamori, M. Ohata, Y. Yamashita, E. Tamura, H. Yoshinari, S. Aihara, F. Minami, H. Mimura and Y. Hagihara, "Proposal of a new CTOD calculation formula," Engineering Fracture Mechanics, 159(2016), 16-34.