S. V. Nizhankovskii, N. S. Sidelnikova, V. V. Baranov, “Optical absorption and color centers in large Ti: Sapphire crystals grown by horizontally directed crystallization under reducing conditions”, Fizika Tverdogo Tela, 57:4 (2015), 763–767; Phys. Solid State, 57:4 (2015), 781–786
