Anggreni, D. M., and I. G. A. Oka Negara. “The Positive Impact of Problem Based Learning Model Toward Students’ Science Knowledge Competence”. Jurnal Ilmiah Sekolah Dasar, vol. 4, no. 4, Mar. 2021, pp. 589-95, doi:10.23887/jisd.v4i4.26282.