Chantarasmai, K., and S. Sindhuchao. “Improvement of vehicle routes with the iterated local search method case study: Tongnamkeang shop, Warinchumrab district, Ubon Ratchathani province”. Asia-Pacific Journal of Science and Technology, vol. 17, no. 6, Apr. 2017, pp. 850-61, https://so01.tci-thaijo.org/index.php/APST/article/view/83298.