1 2 3 Zeberg, Hugo; Pääbo, Svante (July 3, 2020). "The major genetic risk factor for severe COVID-19 is inherited from Neanderthals". bioRxiv. doi:10.1101/2020.07.03.186296. hdl:21.11116/0000-0006-AB4F-2. S2CID 220366134. ↑ Moulson, Geir; Associated Press (July 20, 2006).