1. Guan WY, Ni ZY, Hu Y, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med. 2020;382:1708–20.
2. Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020;395:497–506.
3. Zhou F, Yu T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet. 2020;395:1054.
4. Ministry of Health, Italy. Coronavirus disease (COVID-19) situation report in Italy. Rome: Ministry of Health, Italy. [Accessed Jun 2020]. Available from: http://www.salute.gov.it/portale/nuovocoronavirus/dettaglioContenutiNuovoCoronavirus.jsp?lingua=italiano&id=5351&area=nuovoCoronavirus&menu=vuoto
5. Ministerio de Sanidad, Consumo y Bienestar Social. [Internet]. España; c2019. [Accessed Jun 2020]. Disponible en: https://covid19.isciii.es. Royal Decree 463/2020, of March 14, which decrees the state of alarm for the management of health crisis caused by COVID-19.