Yasser Osama, Khaled Hamed Bilal, and Ibrahim Elimam Abdalla. “Comparison Between IPv4 and IPv6 VoIP over WiMAX Traffic”. Technology Horizon Journal (ISSN: 1858-6368), vol. 2, no. 2, Feb. 2018, http://thj.fu.edu.sd/index.php/thj/article/view/33.