1. D.N. de G. Allen, R.V. Southwell Phil. Trans. Roy. Soc. A, 242, 379 (1949).
2. G.I. Barenblatt Zhurnal Prikladnoj Mekhaniki i Tereoticheskoj Fiziki, 4, 3 (in Russian), (1961).
3. B.A. Bilby, A.H. Cottrell, K.H. Swinden Proc. Roy. Soc. A, 272, 304 (1960).
4. B.A. Bilby, A.H. Cottrell, E. Smith, K.H. Swinden Proc. Roy. Soc. A, 279, 1 (1964).
5. D.S. Dugdale J. Mech. Phys. Solids, 8, 100 (1960).