1. World Health Organization. Pneumonia of Unknown Cause. [Cited 31 December 2020]. Available from: https://www.who.int/emergencies/diseaseoutbreak-news/item/2020-DON229
2. World Health Organization. WHO Coronavirus disease (COVID-19) dashboard. [Cited 6 July 2022]. Available from: https://covid19.who.int/
3. Verma AK, Prakash S. Impact of covid-19 on environment and society. J Global Biosci 2020; 9: 7352-7363
4. COVID-19 pathophysiology: A review
5. Covid-19: risk factors for severe disease and death