Mukhtar, Hidayat, and A. Meichaty. “EFFECTIVENESS OF TEACHER CERTIFICATION IN IMPROVING SERVICE PROFESSIONAL SERVICE IN MADRASAH ALIYAH STATE OF JAMBI PROVINCE”. International Journal of Research -GRANTHAALAYAH, vol. 7, no. 12, June 2020, pp. 292-14, doi:10.29121/granthaalayah.v7.i12.2019.323.