1. Devyatykh, G.G., Karpov, Yu.A., and Osipova, L.I., Vystavka-kollektsiya veshchestv osoboi chistoty (Collection Exhibition of High-Purity Substances), Moscow: Nauka, 2003.
2. Nazarenko, V.A., Analiticheskaya khimiya germaniya (Analytical Chemistry of Germanium), Moscow: Nauka, 1973.
3. Medvedev, N.S., Shaverina, A.V., Tsygankova, A.R., and Saprykin, A.I., Talanta, 2016, no. 155, p. 358.
4. Petrova, N.I., Tsygankova, A.R., and Saprykin, A.I., Inorg. Mater., 2015, vol. 51, no. 1. P. 57.)
5. Chanysheva, T.A., Shelpakova, I.R., and Saprykin, A.I., Zavod. Lab.,Diagn. Mater., 2009, vol. 75, no. 1, p. 7.