KURNIATUN, T. PENERAPAN PROBLEM SOLVING UNTUK MENINGKATKAN AKTIVITAS SISWA MELALUI TUTOR SEBAYA SMP NEGERI 2 AMBULU - JEMBER. Education Journal : Journal Educational Research and Development, [S. l.], v. 1, n. 1, p. 76–82, 2018. Disponível em: https://jurnal.unipar.ac.id/index.php/ej/article/view/81. Acesso em: 10 mar. 2025.