1. O, K. Botvinkin, Physical Chemistry of Silicates [in Russian] (Industrial Construction Press, 1955).
2. G. G. Sentyurin, “A new method for determination of the viscosity of glass,” Trans. MKhTI, No. 18 (1952) [USSR].
3. S. I. Mitrofanov, Investigation of Ores for Beneficiation [in Russian] (Metallurgy Press, 1954).