PASARIBU, R. Pemberian Penguatan (Reinforcement) Terhadap Prestasi Belajar PAK Siswa. KERUGMA: Jurnal Teologi dan Pendidikan Agama Kristen, [S. l.], v. 3, n. 2, p. 68–78, 2021. DOI: 10.2500/kerugma.v3i2.69. Disponível em: http://sttiimedan.ac.id/e-journal/index.php/kerugma/article/view/69. Acesso em: 4 may. 2026.