Dullayaanukij, Sompong. 2021. “The Comparative Study of the Management Effectiveness of Mountain Tourism by E-tag Car Between Phupapox Conservative Tourism Club and Phuborbit Tourism Promotion Club, Loei Province”. Research and Development Journal, Loei Rajabhat University 16 (57):89-99. https://so05.tci-thaijo.org/index.php/researchjournal-lru/article/view/242686.