Siregar H. PENINGKATAN KOMPETENSI GURU MENERAPKAN MODEL PEMBELAJARAN PROBLEM BASED LEARNING (PBL) MELALUI WORKSHOP BAGI GURU MATA PELAJARAN KELAS IX DI UPT SMP NEGERI 20 MEDAN. jetl [Internet]. 2020Dec.6 [cited 2024Nov.26];1(3):41-5. Available from: https://pusdikra-publishing.com/index.php/jetl/article/view/47