1. ASTM E1290 (1989) Standard test method for crack-tip opening displacement (CTOD) fracture toughness measurement
2. BS 7448: Part 1 (1991) Fracture mechanics toughness tests. Part 1. Method for determination of KIC, critical CTOD and critical J values of metallic materials
3. Quantifying pop-in severity in fracture toughness test;Dawes;Fatigue Fracture Engineering in Material Structures,1991
4. Arimochi K., Isaka K. A study on pop-in phenomenon in CTOD test for weldment and proposal of assessment method for significance of pop-in. IIW Doc.X-1118-86, 1986
5. Significance of pop-in fracture toughness testing;Willoughby;International Journal of Fracture,1986