Phanthunane, Pudtan, Chalermpat Pongajarn, and Pakchira Nugbanleng. “Economic Evaluation of Transport Companies Which Operates in Accordance with the ISO39001 Road Safety Standard System”. Journal of Business, Innovation and Sustainability (JBIS) 17, no. 2 (June 20, 2022). accessed March 14, 2025. https://so02.tci-thaijo.org/index.php/BECJournal/article/view/255190.