ตมกลาง นุจรินทร์, and จันทร์ดี ดวงพร. “A Study of Problems and Development of Nondestructive Inspection Personnel”. Siam University Journal of Business Administration 15, no. 24 (March 27, 2022): 124–132. accessed August 13, 2025. https://so07.tci-thaijo.org/index.php/sujba/article/view/836.