Haider, H. M. J. “Calculated of Vibrational Frequencies for Molecular System from Sulphur-Halides in the Infrared Region by Using the Semi Empirical Programs”. Al-Qadisiyah Journal of Pure Science, Vol. 20, no. 1, Aug. 2017, pp. 146-58, https://journalsc.qu.edu.iq/index.php/JOPS/article/view/440.