Hendrawaty, N., T. Angkarini, and A. B. Retnomurti. “EFL Undergraduate Students’ Perceptions of Online Learning Applications During the COVID-19 Outbreak”. Jurnal Pendidikan Dan Pengajaran, vol. 54, no. 1, Mar. 2021, pp. 110-9, doi:10.23887/jpp.v54i1.31763.