“French doctors say they found a Covid-19 patient from December”. CNN (2020年5月4日). 2020年10月27日閲覧。 “"Researchers in the US have also started finding evidence that the virus was infecting and killing people earlier than the country's first reported cases."”
alt, Corona-virus Se samling Læs hele samlingen → Coronavirus i Danmark: Sådan skal du forholde dig Her er (2020年3月8日). “Nu er 35 personer i Danmark smittet med coronavirus” (デンマーク語). Politiken. 2020年3月9日閲覧。