[1]
Siregar, A.N. 2025. Transformational leadership of the principal in improving the professional competence of teachers at SMA Negeri 1 Sosopan, Padang Lawas Regency. Holistic Science. 5, 3 (Dec. 2025), 364–370. DOI:https://doi.org/10.56495/hs.v5i3.1535.