THE EFFECTIVENESS OF DISTANCE LEARNING (PJJ) ON UNDERSTANDING THE CONCEPT OF STUDENTS ON SCIENCE SUBJECT IN SMPN KECAMATAN LAREH SAGO HALABAN. universe [Internet]. 30 Desember 2021 [dikutip 14 Agustus 2026];2(2):198-203. Tersedia pada: http://universe.ppj.unp.ac.id/index.php/universe/article/view/105