Keawsriyong, Teerapat, Warit Wipulanusart, Satjapan Leelatanon, Nukul Suksuwan, Jakkarin Weekaew, Quoc Bao Pham, and Pakorn Ditthakit. 2025. “Optimizing Gravity-Fed Sewer Systems Using GRG and PGSL: A Path to Cost-Effective Design”. Engineering, Technology & Applied Science Research 15 (3). Greece:24087-92. https://doi.org/10.48084/etasr.10228.