1. D. A. Matthews, Distance Education: What Is It? Utilization of Distance Education in Higher Education in the United States, IGI Global. Carlow College, USA, 2002.
2. P. Leonardi, “You’re going digital - Now what?,” MIT Sloan Management Review, 2020.
3. Ł. Sułkowski, “Covid-19 Pandemic; Recession, Virtual Revolution Leading to De-globalization?,” J. Intercult. Manag., vol. 12, no. 1, Pages. 1–11, 2020.
4. UNESCO, “School closures caused by Coronavirus (Covid-19),” UNESCO, 2020. [Online]. Available: https://en.unesco.org/themes/education-emergencies/coronavirus-school-closures. [Accessed: 14-Jul-2020].
5. F. Tian, Q. Zheng, and K. M. Chao, “Current and future of technologies and services in smart e-learning,” Serv. Oriented Comput. Appl., vol. 14, no. 1, Pages. 1–3, 2020.