1. The Measurement of Crack Length and Shape during Fracture and Fatigue, C.J. Beevers, ed., Engineering Materials Advisory Services, Cradley Heath, Warley, West Midlands, U.K., 1980.
2. Advances in Crack Length Measurement, C.J. Beevers, ed., Engineering Materials Advisory Services, Cradley Heath, Warley, West Midlands, U.K., 1982.
3. ASTM STP;W. Elber,1971
4. ASTM STP,1988
5. O. Buck, R.B. Thompson, and D.K. Rehbein.J. Nondest. Eval., 1984, vol. 4, pp. 203–12.