Bloom, J., & Cobey, S. (2021, December 12). Opinion | A Scientist’s Guide to Understanding Omicron. The New York Times. https://www.nytimes.com/2021/12/12/opinion/covid-omicron-data.html

Lawton, Graham. ‘Is the Coronavirus Evolving and Will It Become More or Less Deadly?’ New Scientist. Accessed 25 February 2021. https://www.newscientist.com/article/mg24833053-600-is-the-coronavirus-evolving-and-will-it-become-more-or-less-deadly/.