Siringoringo P, Daryanto E, Rahman A. The Role of School Supervisors in Improving Vocational School (SMK) Accreditation in Humbang Hasundutan. IJSBAR. 2017;35(3):160-165. Accessed March 7, 2026. https://www.gssrr.org/JournalOfBasicAndApplied/article/view/7985