ผลประเสริฐ พิมพ์รพี, and วิทยถาวรวงศ์ พรรณพิศ. “The Effectiveness of the Process of Developing the Life Quality of the Elderly under the Sufficiency Economy: A Case Study Lom Kao District, Phetchabun Province”. Journal of Preventive Medicine Association of Thailand 6, no. 3 (July 5, 2018): 240–255. Accessed May 7, 2024. https://he01.tci-thaijo.org/index.php/JPMAT/article/view/132938.