1. Matczynski, M.: Motion of a crack in antiplane state of an elastic strip. Arch. of Mechanics25, 823 (1973).
2. Matczynski, M.: Quasi-static problem of a crack in an elastic strip subject to antiplane state of strain. Arch. of Mechanics25, 851 (1973).
3. Matczynski, M.: Quasi-static problem of a non-homogeneous elastic layer containing a crack. Acta Mechanica19, 153 (1974).
4. Atkinson, C.: Some results on crack propagation in media with spatially varying elastic moduli. Int. J. Fracture II, 619 (1975).
5. Atkinson, C.: A note on some crack problems in a variable modulus strip. (To appear in) Arch. of Mechanics.27, 639 (1975).