[Significance of virus A1 in the epidemic process in influenza].
D058872:Epidemics; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology*; D009975:Orthomyxoviridae
INFLUENZA VIRUSES; INFLUENZA/epidemiology
Znachenie virusa A1 v epidemicheskom protsesse pri grippe.