Supromajakr, I., P. . Putthongsri, P. . Mahapornpong, and W. . Chusakul. “Strategy Development to Promote Tourism in a Second Tiercity at Chiangkhan, Loei Province”. Dhammathas Academic Journal, vol. 22, no. 3, Sept. 2022, pp. 107-16, https://so06.tci-thaijo.org/index.php/dhammathas/article/view/254887.