Harahap, Nurhidayah, et al. “Improving Student Learning Outcomes through Problem Based Learning Model in Islamic Learning at SD Negeri 14 Kotapinang”. Jurnal Pendidikan Profesi Guru, vol. 1, no. 1, Feb. 2023, pp. 167-75, doi:10.22373/jppg.v1i1.6664.