Smallpox in Europe, 1950-1971.
D000293:Adolescent; D000328:Adult; D002648:Child; D004196:Disease Outbreaks / Q000453:epidemiology; D004641:Emigration and Immigration; D005060:Europe; D006801:Humans; D008875:Middle Aged; D012899:Smallpox / Q000453:epidemiology* / Q000517:prevention & control; D014611:Vaccination