1. N. I. Kitaigorodskii (editor), Manual of Glass Production [in Russian], Vol. 1, GSI, Moscow (1965).
2. O. A. Troitskii, ?The strength of glass,? Priroda, No. 4 (1968).
3. Catalogue of Engineering Microcrystalline Glasses [in Russian], Stroiizdat, Moscow (1969).
4. G. N. Kuznetsov, Mechanical Properties of Rocks [in Russian], Ugletekhizdat, Moscow (1947).
5. K. O. Gray and J. D. Stachiw, ?Glass housing for hydrospace lights and instruments?, Trans. ASME Series B,92, No. 2 (1970).