Handoko, H. “The Principal Strategy In Developing Teacher Professional Competence In Islamic Junior High School Al-Jam’iyatul Washliyah Tembung, Deli Serdang District”. International Journal Of Education, Social Studies, And Management (IJESSM), vol. 1, no. 2, Aug. 2021, pp. 58-72, doi:10.52121/ijessm.v1i2.31.