Avanesov, Andranik G., Valeriy V. Galutskiy, Boris V. Ignatyev, Valeriy A. Lebedev, and Elena V. Stroganova. 2005. “Quenching of Cr3+ Luminescence in Stoichiometric Lithium Niobium Crystals”. Ecological Bulletin of Research Centers of the Black Sea Economic Cooperation, no. 4 (December): 59-64. https://vestnik.kubsu.ru/article/view/126.