Sơn, Lê Văn, and Nguyễn Quang Thanh. “Optimization Problems in Telecommunication Networks: A Classification Study”. <i>Journal of Computer Science and Cybernetics</i> 19, no. 4 (July 27, 2012): 382–390. Accessed January 2, 2026. https://vjs.ac.vn/jcc/article/view/1547.