Ghazali, P. L., S. N. M. Fauzi, A. F. Suib, F. A. Md Nawi, S. A. S. Jaaffar, E. N. M. Zain, H. Che Abdul Hamid, H. Juahir, and Sukono. “Mathematical Formulation of River Quality Index Based on Awareness of River Pollution”. Contemporary Mathematics, vol. 6, no. 5, Sept. 2025, pp. 6333-45, doi:10.37256/cm.6520256390.