1. A. H. Cottrell, “The Tewkesbury Symposium on Fracture”, edited by C. J. Osborn (Brown, Prior and Anderson Ltd, 1965) p. 1.
2. A. A. Wells, British Weld. J, 10 (1965) 563.
3. A. S. Tetelman and A. J. Mcevily, “Fracture of Structural Materials” (John Wiley and Sons Inc, New York, 1967).
4. F. A. McClintock, Proc. Roy. Soc. 285 (1965) 58.
5. F. A. McClintock, S. M. Kaplan, and C. A. Berg Jr, Internat. J. Fracture Mech. 2 (1966) 614.