ALIJOYO, Antonius, and Charles R. VORST. 2022. “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 (1):65-71. https://doi.org/10.38142/ijesss.v3i1.159.