[Epidemiology of virus influenza 1957-1958 in the North Rhine-Westphalia district].
D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology*; D009975:Orthomyxoviridae
INFLUENZA/epidemiology
Zur Epidemiologie der Virus-Grippe 1957-1958 im Land Nordrhein-Westfalen.