“Principal Transformational Leadership, School Culture, and Productivity of Medan Johor High School” (2024) PROSIDING SEMINAR NASIONAL KEGURUAN DAN PENDIDIKAN (SNKP), 2, pp. 102–111. Available at: https://www.ejournal.ummuba.ac.id/index.php/SNKP/article/view/2149 (Accessed: 26 February 2026).