V. N. Molchanov, B. A. Maksimov, A. F. Kondakov, T. S. Chernaya, Yu. V. Pisarevskii, V. I. Simonov, “Crystal structure and optical activity of La$_3$Nb$_{0.5}$Ga$_{5.5}$O$_{14}$ and Sr$_3$Ga$_2$Ge$_4$O$_{14}$ single crystals of the langasite family”, Pis'ma v Zh. Èksper. Teoret. Fiz., 74:4 (2001), 244–247; JETP Letters, 74:4 (2001), 222–225
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