1. WHO announces COVID-19 outbreak a pandemic. http://www.euro.who.int/en/health-topics/health-emergencies/coronavirus-covid-19/news/news/2020/3/who-announces-covid-19-outbreak-a-pandemic. Accessed 25 May 2020
2. Remuzzi, A., Remuzzi, G.: COVID-19 and Italy: what next? Lancet 395(10231), 1225–1228 (2020). https://doi.org/10.1016/S0140-6736(20)30627-9
3. Australian Government Department of Health, COVIDsafe application website. https://www.health.gov.au/resources/apps-and-tools/covidsafe-app. Accessed 25 Apr 2020
4. The Chinese QR code scanning based contact tracing application (in Mandarin Chinese). https://mp.weixin.qq.com/s/amB7fBxLw8KSR9DcUsbTWg. Accessed 25 May 2020
5. Israeli Ministry of Health, HaMagen contact tracing application website. https://govextra.gov.il/ministry-of-health/hamagen-app/download-en/. Accessed 25 May 2020