ALIJOYO, Antonius, and Charles R. VORST. “Measuring And Improving The Effectiveness Of ISO 31000 Based Erm In State-Controlled PSO - A Case Study Of Toll Road Operators In Indonesia”. International Journal of Environmental, Sustainability, and Social Science 3, no. 1 (March 31, 2022): 65–71. Accessed June 6, 2026. https://staging.journalkeberlanjutan.com/index.php/ijesss/article/view/159.