Klomjit, Prachuab, Chanpen Anurattananon, Alongkorn Chatmuangpak, and Amnaht Amaluk. 2020. “Efficiency Improvement by Simulation Technique in the Parcel Service Company”. Science & Technology Asia 25 (4):20-29. https://ph02.tci-thaijo.org/index.php/SciTechAsia/article/view/199234.