1. 1) F. Y. Galakhov, V. I. Aver’yanov, V. T. Vavilonova and M. P. Areshev: Sov. J. Glass Phys. Chem., 11 (1985), 712.
2. 2) E. F. Osborn and A. Muan: Phase Equilibrium Diagrams of Oxide Systems, Plate 4. The System Na2O-Al2O3-SiO2, American Ceramic Society, Columbus, OH, (1960), Plate 4.
3. 3) E. F. Osborn and A. Muan: Phase Equilibrium Diagrams of Oxide Systems, Plate 3. The System MgO-Al2O3-SiO2, American Ceramic Society, Columbus, OH, (1960), Plate 3.
4. 4) E. F. Osborn and A. Muan: Phase Equilibrium Diagrams of Oxide Systems, Plate 2. The System CaO-Al2O3-SiO2, American Ceramic Society, Columbus, OH, (1960), Plate 2.
5. 5) A. Navrotsky, G. Peraudeau, P. McMillan and J. P. Coutures: Geochim. Cosmochim. Acta, 46 (1982), 2039.