1. Knauss, W. G.: Applied Mechanics Reviews 26, 1 (1973)
2. Gurney, C., Hunt, J.: Proc. R. Soc. A299 (1967)
3. Griffith, A. A.: Phil. Trans. R. Soc. A221, 163 (1920)
4. Rice, J. R., in: Fracture — an advanced treatise. Liebowitz, H. (ed.). New York/London: Academic Press 1963, Vol. II, Chapter 3
5. Williams, M. L.: J. Appl. Mech. 24, (1) (1957)