Srisuwandee, T., and R. Pitakaso. “Solving Vehicle Routing Problem by Using Ant Colony Optimization Case Study in Jiaranai Drinking Water Company”. Asia-Pacific Journal of Science and Technology, vol. 17, no. 5, Apr. 2017, pp. 706-14, https://so01.tci-thaijo.org/index.php/APST/article/view/83279.