Verifying and Weighting Factors using Fuzzy Delphi Method Approach in The Construction of Public Perception Index (PPI) on River Quality. Contemp. Math. [Internet]. 2025 Jun. 27 [cited 2025 Dec. 24];6(4):3862-7. Available from: https://ojs353.mebyme.cn/index.php/CM/article/view/5842