“THE EFFECTIVENESS OF DISTANCE LEARNING (PJJ) ON UNDERSTANDING THE CONCEPT OF STUDENTS ON SCIENCE SUBJECT IN SMPN KECAMATAN LAREH SAGO HALABAN”. UNIVERSE : Journal of Science Education Teaching and Learning 2, no. 2 (December 30, 2021): 198–203. Accessed October 23, 2026. http://universe.ppj.unp.ac.id/index.php/universe/article/view/105.