Siriratpaibool, W. (2025). Guidelines for estimating an appropriate wastewater treatment system: A case study of Health Region 8, Udon Thani Province. Journal of Health Promotion and Environmental Health Research Health Promotion Centre 8 Udon Thani, 3(3), 48–67. retrieved from https://he04.tci-thaijo.org/index.php/hpc8Journal/article/view/3589