Siriratpaibool, W. “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, vol. 3, no. 3, Sept. 2025, pp. 48-67, https://he04.tci-thaijo.org/index.php/hpc8Journal/article/view/3589.