Kristianto N, Delvia D. LEVELS OF ONLINE LEARNING EFFECTIVENESS IN THE TIME OF THE COVID-19 PANDEMIC USING DIFFERENT APPLICATIONS LEARNING BY STUDENT’S PERCEPTION. epsilon [Internet]. 2022 Apr. 19 [cited 2024 Jul. 3];3(1). Available from: https://jurnal.stkippgribl.ac.id/index.php/epsilon/article/view/583