Hussain, Nahla. “Wavelength Division Multiplexing Passive Optical Network Modeling Using Optical System Simulator”. Al-Khwarizmi Engineering Journal 11, no. 3 (June 30, 2015): 61-71. Accessed April 21, 2021. https://alkej.uobaghdad.edu.iq/index.php/alkej/article/view/255.