Siburian, Tiur Asi, Nurhayati Simatupang, and Hera Chairunisa. “Model Development of Principal Performanc Through Empirical Study on Junior High School in Medan Indonesia”. International Journal of Sciences: Basic and Applied Research (IJSBAR) 31, no. 1 (January 13, 2017): 248–259. Accessed May 9, 2024. https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/6490.