DEVELOPMENT OF LKPD MODEL DISCOVERY LEARNING ACTIVITY ORIENTED CRITICAL THINKING ON VIBRATION MATERIALS, WAVES, AND SOUND FOR LEARNING IPA CLASS VIII IN JUNIOR HIGH SCHOOL 13 PADANG. universe [Internet]. 16 Juni 2021 [dikutip 16 Agustus 2026];2(1):18-24. Tersedia pada: http://universe.ppj.unp.ac.id/index.php/universe/article/view/34