1. P. C. Paris and G. Sih, Fracture Toughness Testing and its application,A.S.T.M., S.T.P. 381, 30?81.
2. A. A. Wells, Unstable crack propagation in metals-cleavage and fast fracture,Cranfield Crack Propagation Symposium 1 (1961) 210.
3. T. Kanazawa, S. Machida, S. Momota and Y. Hagiwara,A study of the crack opening displacement (COD) concept for brittle fracture initiation, 2nd Internat. Conf. onFracture (U.K.) (1969).
4. M. Liddle and K. J. Miller,Multiaxial High Strain Fatigue, 3rd Internat. Conf.Fracture (Munich) (1973).
5. M. W. Brown and K. J. Miller,A theory for fatigue failure under multiaxial stress-strain conditions, Cambridge University Engineering Department Report 1972, CUED/C.-Mat/TR5.