Qamar, F., M. Khawar, M. Zafarullah, and A. Shahzad. “Optimization of Gain Flattening Filter to Achieve Flat Gain of EDFA for DWDM Chaotic Communication”. Technical Journal, Vol. 23, no. 04, Dec. 2018, pp. 46-52, https://tj.uettaxila.edu.pk/index.php/technical-journal/article/view/699.