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2. 2) British Standards Institution "Methods for crack opening displacement testing-COD-DD19". 1972".
3. 4) American Society for Testing and Materials "Standard test method for linear-elastic plane strain fracture toughness KIc of metallic materials.", ASTM E399-1974.
4. 5) Michael. G. Daws, "Application of Fracture Mechanics to Brittle Fracture in Steel Weld Metals", Ph.D. Thesis, The Welding Institute, London, England, Dec.1976.
5. 6) M. G. Dawes, Elastic-Plastic fracture, ASTM STP 668, pp.307-333. ASTM, Philadelphia,1979.