F. Abdel-Wahab, I. M. Ashraf, F. B. Ahmed, “Optical parameters of both As$_2$S$_3$ and As$_2$S$_3$ thin films from ultraviolet to the near-infrared via variable-angle spectroscopic ellipsometer”, Fizika i Tekhnika Poluprovodnikov, 54:11 (2020), 1217; Semiconductors, 54:11 (2020), 1430–1438
