1. Genomic characterisation and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding;R Lu;Lancet,2020
2. “World Health Organization.” WHO characterizes COVID-19 as a pandemic. 2020 [cited 14 Mar 2020]. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/events-as-they-happen
3. “World Health Organization.” Daily data on coronavirus (COVID-19). 2020 [cited 30 Apr 2020]. https://covid19.who.int/
4. Recurrent PCR positivity after hospital discharge of people with coronavirus disease 2019 (COVID-19);D Jiang;J Infect,2020
5. Positive RT-PCR Test Results in Patients Recovered from COVID-19;L Lan;JAMA,2020