ศรีปากดี นฤพนธ์, and ศรีพุทธรินทร์ สุมาลี. 2016. “Situations of Implementation in Non-Formal Education Based on Students’ Perceptions under Non-Formal Education and Informal Education Center in Chanpen Sub-District, Tao-Ngoi District, Sakon Nakhon Province”. RMUTI JOURNAL Humanities and Social Sciences 3 (1):104-13. https://so05.tci-thaijo.org/index.php/RMUTI_SS/article/view/193664.