MELINA, M.; PASARIBU, I. L. . .; SIMANJUNTAK, L. . . The Analysis of Online Learning PKN in the Covid-19 Pandemic of SMP Negeri 2 Lintongnihuta Humbang Hasundutan Regency. Jurnal Mantik, [S. l.], v. 5, n. 3, p. 1775-1781, 2021. Disponível em: https://iocscience.org/ejournal/index.php/mantik/article/view/1749. Acesso em: 19 apr. 2026.