Eamsiri, S., and K. Suthiwartnarueput. “Process Improvement in Issuing Certificate of Origin by Ministry of Commerce with Simulation Model”. Burapha Science Journal, vol. 26, no. 2 May-August, Mar. 2026, pp. 1164-85, https://li05.tci-thaijo.org/index.php/buuscij/article/view/1426.