1. Smallpox and its eradication;Fenner,1988
2. Smallpox as a biological weapon;Henderson;JAMA,1999
3. Smallpox in history: the birth, death, and impact of a dread disease;Eyler;J Lab Clin Med,2003
4. Clinical investigaton of smallpox in 1767;Boylstom;N Engl J Med,2002
5. An inquiry into the causes and effects of the variolae vaccinae: a disease discovered in some of the western counties of England, particulary Gloucestershire, and known by the name of the cow pox;Jenner,1978