E. Hadzieva, J. Guncaga, S. C. Bose, and K. S. Ivanoska, “Introductory Survey on Challenges Encountered by University Teachers in Online Teaching of STEM Subjects During COVID-19 Lockdown”, CEJER, vol. 3, no. 3, pp. 22–32, Nov. 2021, doi: 10.37441/cejer/2021/3/3/9601.