Nuraida D, isnani isnani. VALIDITAS MODUL BIOLOGI KELAS VII BERBASIS PROBLEM SOLVING PADA MATERI PENCEMARAN LINGKUNGAN. snasppm [Internet]. 2021 May 20 [cited 2026 Apr. 28];5(2):251-6. Available from: https://prosiding.unirow.ac.id/index.php/SNasPPM/article/view/416