Siti Rahmawati. UPAYA MENINGKATKAN HASIL BELAJAR SISWA DENGAN MODEL PBI ( PROBLEM BASED INTRODUCTION ) PADA MATERI PENCEMARAN LINGKUNGAN DI KELAS VIIA MTS-SA DARUL ULUM MAUK. JPBB [Internet]. 2022 Dec. 9 [cited 2026 Jun. 30];1(4):103-17. Available from: https://globalnusapress.org/index.php/jpbb/article/view/851