1. M. M. Shults and O. V. Mazurin, Modern Ideas of the Structure and Properties of Glass [in Russian], Nauka, Leningrad (1988), p. 320.
2. N. N. Kachalov, Glass [in Russian], Izd. Akad. Nauk SSSR, Moscow (1959), p. 465.
3. A. Lukas, Ancient Egyptian Materials and Industries, Edward Arnold, London (1934).
4. Yu. L. Shchapova, Essays on the History of Ancient Glassmaking [in Russian], Izd. Mosk. Gos.Univ., Moscow (1983), p. 200.
5. M. A. Bezborodova, Chemistry and Technology of Ancient and Medieval Glass [in Russian], Nauka i Tekhnika, Minsk (1969), p. 274.