รัตนโอฬาร ธ. THE DEVELOPMENT OF A MULTI-LEVEL STRUCTURAL EQUATION MODEL OF TRANSFORMATIONAL LEADERSHIP OF UNDERGRADUATE STUDENTS IN BUSINESS ADMINISTRATION. JAR [internet]. 2020 Apr. 8 [cited 2026 Sep. 10];18(2):141-54. available from: https://so04.tci-thaijo.org/index.php/jar/article/view/241017