1. Cucinotta, D., & Vanelli, M. (2020). WHO declares COVID-19 a pandemic. Acta Biomedica, 19, 91(1), 157-160. https://doi:10.23750/abm.v91i1.9397
2. Daggett, W. R. (2016). Rigor/relevance framework: A guide to focusing resources to increase student performance. International Center for Leadership in Education, https://leadered.com, https://bit.ly/3vyHjI9
3. Daggett, W. R., & Nussbaum, P. D. (2008). How brain research relates to rigor, relevance and relationships. http://citeseerx.ist.psu.edu, https://bit.ly/3C6YUt5
4. Harris, M. (2011). Using YouTube to enhance student engagement. Faculty Focus. Focused on Today’s Higher Education Professional, https://www.facultyfocus.com, https://bit.ly/2ZinVn4
5. Jandhyala, D. (2017). Visual Learning: 6 Reasons why visuals are the most powerful aspect of e-learning. https://elearningindustry.com , https://bit.ly/3C4Q6nr