1. Hagman, L.O. and Kierkegaard, P., Acta Chem. Scand., 1968, vol. 22, no. 6, pp. 1822–1832.
2. Pet’kov, V.I. and Asabina, E.A., Steklo Keramika, 2004, no. 7, pp. 23–29.
3. Brownfield, M.E., Foored, E.E., Sutley, S.J., and Botinelly, T., Am. Mineralogist. 1993, vol. 78, pp. 653–656.
4. Pet’kov, V.I. and Orlova, A.I., Neorg. Mater., 2003, vol. 39, no. 10, pp. 1177–1188.
5. Ekologocheskaya khimiya (Chemistry of Environmental safety), Korte, F., Moscow: Mиp, 1997.