1. ASTM Standard Test Method for JIc, A Measure of Fracture Toughness, E813-89
2. ASTM Standard Test Method for Crack - Tip Opening Displacement (CTOD) Fracture Toughness Measurement, E1290-89
3. BS 5762: 1979, “Methods for Crack Tip Opening Displacement (COD) Testing,” British Standards Institution, London, 1979
4. Singular behaviour at the end of a tensile crack in a hardening material
5. Plane strain deformation near a crack tip in a power-law hardening material