สัตโยภาส ส. (2018) “An Application of Enneagram to Explore Causal Factors Influencing Different Personality Types: Case Study of Bachelor Degree Students, Rajabhat University”, Journal of Graduate Research, 9(2), pp. 113–129. Available at: https://so02.tci-thaijo.org/index.php/banditvijai/article/view/134763 (Accessed: 29 April 2024).