Nasution, Novita Sari, Ika Chastanti, dan Dahrul Aman Harahap. “PROFILE OF STUDENTS DIFFICULTY IN BIOLOGY LEARNING DURING PANDEMIC COVID-19 IN SMA NEGERI 1 SILANGKITANG”. Jurnal Pelita Pendidikan 9, no. 1 (Maret 31, 2021). Diakses Juli 12, 2025. https://jurnal.unimed.ac.id/2012/index.php/pelita/article/view/22205.