text: *McMillan P.W., "The glass phase in glass-ceramics", Glass Technology, 1974, Vol. 15 (1), P. 5-15
  *Bach H. (Editor), "Low thermal expansion glass ceramics", Springer-Verlag (1995).
  *Holand, Wolfram and Beall, George H. Glass-Ceramic Technology. Wiley, 2002.