รัตนโอฬาร ธ. (2020) “THE DEVELOPMENT OF A MULTI-LEVEL STRUCTURAL EQUATION MODEL OF TRANSFORMATIONAL LEADERSHIP OF UNDERGRADUATE STUDENTS IN BUSINESS ADMINISTRATION”, Journal of the Association of Researchers, 18(2), pp. 141–154. available at: https://so04.tci-thaijo.org/index.php/jar/article/view/241017 (accessed: 11 September 2026).