บุญภิละ นวรัตน์. “Designing and Developing of Pearl Decorative Souvenir; Ban Nonglad, Thonnalab Sub-District, Ban Dung District, Udon Thani Province”. Mahachula Academic Journal 6, no. ฉบับพิเศษ (May 20, 2019): 51–65. Accessed May 5, 2024. https://so04.tci-thaijo.org/index.php/JMA/article/view/181005.