1. M.I. Ravich: Zh. Neorg. Khim. 15, 2019 (1970)
2. M.I. Ravich, F.E. Borovaya: Zh. Neorg. Khim. 9, 952 (1964)
3. S. Sourirajan, G. Kennedy: Am. J. Sci. 260, 115 (1962)
4. V.K. Yanovsky, V.I. Voronkova, V.A. Koptsik: Kristallografiya 15 362 (1970) [English transi.: Sov. Phys. Crystallogr.15, 302 (1970)]
5. T.G. Petrov, E.B. Treivus, A.P. Kasatkin: Vyrashchivaniye kristallov iz vodnykh rastvorov (Crystal Growth from Aqueous Solutions) ( Nedra, Leningrad 1967 )