Smallpox eradication. A global appraisal.
D003140:Communicable Disease Control; D005381:Financing, Organized; D006801:Humans; D007391:International Cooperation; D012899:Smallpox / Q000191:economics / Q000517:prevention & control*; D014611:Vaccination / Q000191:economics / Q000379:methods; D014944:World Health Organization