H. Margaryan, N. Hakobyan, V. Abrahamyan, V. Belyaev, D. Chausov, and A. Spakhov, “NEW GENERATION OPTICAL ELEMENTS WITH CENTRALLY SYMMETRIC ORIENTATION BASED ON LIQUID CRYSTAL POLYMERS”, Proc. YSU A: Phys. Math. Sci., vol. 54, no. 1 (251), pp. 70–76, Apr. 2020.