1. G. Green, R. F. Smith andJ. F. Knott, ?Metallurgical Factors in Low Temperature Slow Crack Growth?, British Steel Corporation Conference on the Mechanics and Mechanisms of Crack Growth, Cambridge, April, 1973, Paper 5.
2. J. D. G. Groom andJ. F. Knott, ?Effects of Pre-strain on Ductile Fracture?, First International Conference on Mechanical Behaviour of Materials, Kyoto, Japan, 1971. Vol. 1, pp. 265?275.
3. Y. W. Mai andK. M. Pilko,J. Mater. Sci. 14 (1979) 386.
4. B. Cotterell andJ. K. Reddel,Int. J. Fracture,13 (1977) 267.
5. B. Cotterell andY. W. Mai, to be presented at the Fifth International Conference on Fracture, Cannes, France, 1981.