wati, Ira, et al. “PENGARUH MODEL PEMBELAJARAN PROBLEM CENTERED LEARNING (PCL) TERHADAP KEMAMPUAN BERPIKIR”. Jurnal Prodi Pendidikan Matematika (JPPM), vol. 1, no. 1, Jan. 2020, pp. 1-10, https://jurnal.mipatek.ikippgriptk.ac.id/index.php/JPPM/article/view/7.