Influenza: a historical perspective.
D004196:Disease Outbreaks / Q000266:history*; D014943:Global Health; D049669:History, 16th Century; D049673:History, 20th Century; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology / Q000266:history*; D009975:Orthomyxoviridae / Q000145:classification