Astyaningrum, Sucia, and Suyitno YP. 2018. “EFEKTIVITAS MODEL PROBLEM BASED LEARNING TERHADAP PENILAIAN KOGNITIF SUBTEMA KESEIMBANGAN EKOSISTEM KELAS V SD”. JS (JURNAL SEKOLAH) 2 (1):102-6. https://doi.org/10.24114/js.v2i1.9927.