1. Mushinskii, V.P. and Karaman, M.I., Opticheskie svoistva khal’kogenidov galliya i indiya (Optical Properties of Gallium and Indium Chalcogenides), Chisinau: Shtiintsa, 1973.
2. Fischer, G., Speculation of the Band Structure of the Layer Compounds GaS and GaSe, Helv. Phys. Acta, 1963, vol. 36, no. 3, pp. 1313–1325.
3. Alekperov, O.Z., Near-Edge and Ultraviolet Photoconductivity of Gamma-Irradiated InSe, Neorg. Mater., 1999, vol. 35, no. 11, pp. 1315–1320 [Inorg. Mater. (Engl. Transl.), vol. 35, no. 11, pp. 1125–1129].
4. Alekperov, O.Z. and Zarbaliev, M.Z., Effect of Sulfur Vacancies on Photoconductivity in Gallium Sulfide, Neorg. Mater., 1998, vol. 34, no. 10, pp. 1163–1167 [Inorg. Mater. (Engl. Transl.), vol. 34, no. 10, pp. 971–975].
5. Kamimara, H. and Nakao, K., Band Structure and Optical Properties of Semiconducting Layer Compounds GaS and GaSe, J. Phys. Soc. Jpn., 1968, vol. 24, no. 6, pp. 1313–1325.