1. M. M. Filonenko-Borodich, Mechanical Theories of Strength [in Russian], Izd. MGU, Moscow (1961).
2. K. V. Ruppeneit, The Mechanical Properties of Rocks [in Russian], Ugletekhizdat, Moscow (1956).
3. R. M. Éigeles and Yu. Ya. Éstrin, Fiz.-Tekh. Probl. Razrabotki Polezn. Iskop., No. 6 (1965).
4. Yu. N. Rabotnov, Strength of Materials [in Russian], Moscow (1962).
5. S. N. Zhurkov and É. E. Tomashevskii, in: “Some problems in the strength of solids,” [in Russian], Moscow-Leningrad (1959).