The incidence of influenza among persons of different economic status during the epidemic of 1918. 1931.
Edgar
E
Sydenstricker
D004196:Disease Outbreaks / Q000266:history*; D049673:History, 20th Century; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology / Q000266:history*; D012923:Social Class; D014481:United States / Q000453:epidemiology