1. ASTM E399-83, in “Standard Test Method for Plane Strain Fracture Toughness of Metallic Materials,≓1983 Annual Book of ASTM Standards, Section 3, American Society for Testing and Materials, Philadelphia, PA, 1983, pp. 170-553.
2. ASTM E813-81, in “Standard Test Method forJIc, a Measure of Fracture Toughness,≓ibid., pp. 762-80.
3. J. A. Begley and J. D. Landes: inFracture Toughness, ASTM STP 514, American Society for Testing and Materials, Philadelphia, PA, 1974, pp. 170–86.
4. J.F. Knott: inFundamentals of Fracture Mechanics, Butterworths, London, 1973.
5. C.F. Shih:J. Mech. Phys. Solids, 1981, vol. 29, pp. 305–30.