Vartanyan, A.L., et al. “EFFECTS OF ELECTRIC FIELD AND IMAGE CHARGES ON THE IMPURITY-RELATED OPTICAL ABSORPTION COEFFICIENTS IN A SPHERICAL QUANTUM DOT”. Proceedings of the YSU A: Physical and Mathematical Sciences, vol. 51, no. 1 (242), Mar. 2017, pp. 124-7, doi:10.46991/PYSU:A/2017.51.1.124.