1. J.R. Dixson and J.S. Strannigan: Proc. 2nd Int. Conf. Frac., London (1969), pp.105-118.
2. E.K. Walker: AFFDL-TR-66-92, Wright-Patterson AFB, Ohio (1966).
3. R.G. Forman: AFFDL-TR-65-146, Wright-Patterson AFB, Ohio (1966).
4. B.L. Clarkson: Acoustical Fatigue in Aerospace Structure, (Syracuse University Press 1965).
5. S.A. Pietrusewicz: J. Sound Vibration Vol. 11, No. 2 (1970), pp.235-250.