Thaweephawilai, P., M. Uthansakul, C. Prommak, and C. Wechtaisong. “Power Level Assignment and Base Station Placement Using Simulated Annealing for 4G-LTE Femtocell Networks in Multi-Floor Buildings”. Applied Science and Engineering Progress, vol. 13, no. 3, July 2020, pp. 246-55, https://ph02.tci-thaijo.org/index.php/ijast/article/view/241544.