Adedoyin, O. B., & Soykan, E. (2020). COVID-19 pandemic and online learning: the challenges and opportunities. Interactive Learning Environments. Advance online publication. https://doi.org/10.1080/10494820.2020.1813180

Agormedah, E. K., Henaku, E. A., Ayite, D. M. K., & Ansah, E. A. (2020). Online Learning in Higher Education during COVID-19 Pandemic: A case of Ghana. Journal of Educational Technology & Online Learning, 3(3),183-210. https://doi.org/10.31681/jetol.726441

Allen, E., & Seaman, J. (2013). Changing course: Ten years of tracking online education in the United States. Babson Survey Research Group.

Thien-Vu, G. (2020). The impact of salary and social welfare on working motivation of Vietnamese official-lecturers: passion overcomes the difficulties. Global Journal of Human-Social Science: Linguistics & Education, 20(6), 33-42.

Baskarada, S. (2014). Qualitative case study guidelines. The Qualitative Report, 19(40), 1-25. https://doi.org/10.46743/2160-3715/2014.1008

Braun, V., & Clarke, V. (2006). Using thematic analysis in psychology. Qualitative research in psychology, 3(2), 77-101. https://doi.org/10.1191/1478088706qp063oa  

Cong, S., & Duc, T. (2017, March 21). Online education: which model will succeed? Nhip cau dau tu [Invested Bridge]. https://bit.ly/3l8Hyor

David, P., Pellini, A., Jordan, K., & Phillips, T. (2020, April 15). Education during the COVID-19 crisis: Opportunities and constraints of using EdTech in low-income countries. The Edtech Hub. https://bit.ly/3ngCeC9

Dhawan, S. (2020). Online learning: A panacea in the time of COVID-19 crisis. Journal of Educational Technology Systems, 49(1), 5-22. https://doi.org/10.1177/0047239520934018  

Dinh-Thai, D., Thien-Vu, G., Van-Son, H., Thanh-Huan, N., & Vinh-Khuong, N. (2020). Projection in education: Conditions for the sustainable development of Vietnamese education. European Journal of Educational Research, 9(1), 179-185. https://doi.org/10.12973/eu-jer.9.1.179  

Dumford, A. D., Miller, A. L. (2018). Online learning in higher education: exploring advantages and disadvantages for engagement. Journal of Computing in Higher Education, 30, 452–465. https://doi.org/10.1007/s12528-018-9179-z

Dung, T. K., & Thuy, T. T. (2020). Motivation, satisfaction, and intention to continue learning online: applying the theory of use and satisfaction during the COVID-19 pandemic. Asian Journal of Economic and Business Studies, 31(1), 5-28.

Hanh, T. T. B. (2017). Benefits and necessity to awaken about online education in Vietnam - a closer look at the role of online education in Vietnamese universities - online training during the industrial revolution 4.0. National Economics University Publishing House.

Hodges, C., Moore, S., Lockee, B., Trust, T., & Bond, A. (2020). The difference between emergency remote teaching and online learning. Educause Review, 27(1), 1-9.

Jalli, N. (2020). Lack of internet access in Southeast Asia poses challenges for students to study online amid the COVID-19 pandemic. The Conversation. https://bit.ly/3BUbETt

Johnson, N., Veletsianos, G., & Seaman, J. (2020). US faculty and administrators' experiences and approaches in the early weeks of the COVID-19 pandemic. Online Learning, 24(2), 6-21. https://doi.org/10.24059/olj.v24i2.2285

Krajewski, M., Frąckowiak, M., Kubacka, M., & Rogowski, Ł. (2020). The bright side of the crisis. The positive aspects of the COVID-19 pandemic according to the Poles. European Societies. Advance online publication. https://doi.org/10.1080/14616696.2020.1869283

Linh, N. V. (2017). Application of e-learning at faculty of information technology & communication - Can Tho university. Institute of Educational Management Publishing House.

Long, L. D., & Ly, N. T. T. (2020). Designing pedagogical script for short-term online courses. Ho Chi Minh City University of Education Journal of Science, 17(8), 1361-1372.

Ministry of Education and Training. (2017). Circular No. 21/2017/TT-BGDDT, on regulations on the application of information technology in Internet training and training for teachers, staff, and educational administrators, was issued on September 6 the year 2017. Vietnamese Government Publishing Service. https://bit.ly/3nfW0h0

Ministry of Education and Training. (2018a). Official dispatch No. 5807/BGDDT-CNTT on guiding the deployment of IT application models in high schools, issued on December 21, 2018. Vietnamese Government Publishing Service. https://bit.ly/3yYQ6mT

Ministry of Education and Training. (2018b). National education program - master program and subject program. Issued together with the circular No. 32/2018/TT-BGDDT dated December 26, 2018, of the minister of education and training. Vietnamese Government Publishing Service. https://bit.ly/3z1zniG

Ministry of Education and Training. (2020a). Official Letter No. 4003/BGDDTCNTT on guiding the implementation of IT tasks in the academic year 2020-2021, issued on October 7, 2020. Vietnamese Government Publishing Service. https://bit.ly/3yRpV1m

Ministry of Education and Training. (2020b). Circular No. 37/2020/TT-BGDDT, providing for the organization, operation, and use of e-mails and web portals at the department of education and training and preschool and general education institutions, continuing education, issued on October 5, 2020. Vietnamese Government Publishing Service. https://bit.ly/3jTplfk

Ministry of Education and Training. (2020c, December 29). Renovate education and training for the sake of sustainable development. https://bit.ly/3hdtdpC

Ministry of Health Portal. (2020). Summary of the prevention of the COVID-19 epidemic in 2020. https://bit.ly/3nfVOOO

Morris, A. (2015). A practical introduction to in-depth interviewing. Sage.

Nambiar, D. (2020). The impact of online learning during COVID-19: students' and teachers' perspectives. The International Journal of Indian Psychology, 8(2), 783-793. https://doi.org/10.25215/0802.094  

Oanh, L. T. M., & Thuy, N. T. N. (2020). Assess the effectiveness of students' online learning in the COVID-19. VNU Journal of Science: Education Research, 37. https://doi.org/10.25073/2588-1159/vnuer.4445  

Pollack, P. H., & Wilson, B. M. (2002). Evaluating the impact of internet teaching: Preliminary evidence from American national government classes. Political Science and Politics, 35(3), 561–566. https://doi.org/10.1017/S1049096502000847

Restauri, S. L., King, F. L., & Nelson, J. G. (2001). Assessment of students’ ratings for two methodologies of teaching via distance learning: An evaluative approach based on accreditation. ERIC. https://files.eric.ed.gov/fulltext/ED460148.pdf

Saavedra, J. (2020). Educational challenges and opportunities of the Coronavirus (COVID-19) pandemic. World Bank Blogs. https://bit.ly/3lbbr7A

Sarwar, H., Akhtar, H., Naeem, M. M., Khan, J. A., Waraich, K., Shabbir, S., Hasan, A., & Khurshid, Z. (2020). COVID-19 pandemic and challenges of dentistry: self-reported effectiveness of e-learning classes during COVID-19 pandemic: a nation-wide survey of Pakistani undergraduate dentistry students. European Journal of Dentistry. Advance online publication. https://doi.org/10.1055/s-0040-1717000  

Schneider, S. L., & Council, M. L. (2020). Distance learning in the era of COVID-19. Archives of dermatological research. Advance online publication. https://doi.org/10.1007/s00403-020-02088-9

Snyder, T. D., de Brey, C., and Dillow, S. A. (2016). Digest of Education Statistics 2014 (50^th ed.). National Center for Education Statistics, Institute of Education Sciences, U.S. Department of Education. https://nces.ed.gov/pubs2016/2016006.pdf

Tam, N. T. (2017). Challenges and solutions for online training in Vietnam during the time to promote education through digital - online training in the industry revolution 4.0. National Economics University Publishing House.

Tang, T., Abuhmaid, A. M., Olaimat, M., Oudat, D. M., Aldhaeebi, M., & Bamanger, E. (2020). The efficiency of a flipped classroom with online-based teaching under COVID-19. Interactive Learning Environments. Advance online publication. https://doi.org/10.1080/10494820.2020.1817761

Taylor-Guy, P., & Chase, A. M. (2020). Universities need to train lecturers in online delivery, or they risk students dropping out. The Conversation. https://bit.ly/3E1C47v

Thai, V. T. (2017). The situation of online training model at university of education - Thai Nguyen University. Institute of Educational Management Publishing House.

Tham, D. H., Ha, N. D., & Quyen, V. T. (2020). Benefits and restrictions of the life online home exercise software in Vietnam. TNU Journal of Science and Technology, 225(12), 3-9. https://doi.org/10.34238/tnu-jst.2844

Thanh, P. T. N., Thong, N. N., & Thao, N. T. P. (2020). Perception of undergraduate students when experiencing completely online learning during COVID-19 epidemic prevention. Ho Chi Minh City Open University Journal of Science - Social science, 15(3), 1-12.

Thuan, T. Q., & Hong, B. V. (2020). Management of online teaching in technical universities in Ho Chi Minh City. Ho Chi Minh City Open University Journal of Science - Social science, 15(1), 1-15.

United Nations Educational, Scientific and Cultural Organization. (2020a). Coronavirus deprives nearly 300 million students of their schooling. https://bit.ly/3hjgD8t

United Nations Educational, Scientific and Cultural Organization. (2020b). 290 million students out of school due to COVID-19: UNESCO releases first global numbers and mobilizes response. https://bit.ly/3jWDsR5

World Bank. (2020a). Guidance note on remote learning & COVID-19. https://bit.ly/38SEWFv

World Bank. (2020b). Rapid response guidance note: Educational television and COVID-19 (English). https://bit.ly/3BVmtVd  

Yamaguchi, K., Takebayashi, Y., Miyamae, M., Komazawa, A., Yokoyama, C., & Ito, M. (2020). Role of focusing on the positive side during COVID-19 outbreak: Mental health perspective from positive psychology. Psychological Trauma: Theory, Research, Practice, and Policy. Advance online publication. https://doi.org/10.1037/tra0000807  

Zhu, X., & Liu, J. (2020). Education in and after COVID-19: Immediate responses and long-term visions. Postdigital Science and Education, 2(3), 695-699. https://doi.org/10.1007/s42438-020-00126-3