Reni Tania, and Welven Aida. 2021. “PENGARUH MODEL PEMBELAJARAN PROBLEM BASED LEARNING TERHADAP KEMAMPUAN BERPIKIR KRITIS SISWA KELAS IX MATA PELAJARAN IPS DI SMP NEGERI 1 BANGUN PURBA”. Bakoba : Journal of Social Science Education 1 (1):24-33. https://journal.upp.ac.id/index.php/bakoba/article/view/587.