1. A. A. Kaminskii, Fracture Mechanics of Viscoelastic Solids [in Russian], Naukova Dumka, Kiev (1980).
2. Yu. N. Rabotnov, Elements of Hereditary Mechanics of Solids [in Russian], Nauka, Moscow (1977).
3. V. G. Gromov, ?Mathematical content of the Volterra principle in the boundary viscoelasticity problem,? Prikl. Mat. Mekh., No. 5, 869?878 (1971).
4. V. G. Gromov, ?The problem of solving boundary problems of linear viscoelasticity,? Mekh. Polim., No. 6, 999?1011 (1967).
5. V. V. Panasyuk, Limiting Equilibrium of Bodies with Cracks [in Russian], Naukova Dumka, Kiev (1968).