1. World Health Organization. The global eradication of smallpox: final report of the Global Commission for the Certification of Smallpox Eradication, Geneva, December 1979. World Health Organization 1980, 1–122.
2. Smallpox containment updated: considerations for the 21st century;Heymann;Int J Infect Dis,2004
3. Shining light on “Dark Winter”;O’Toole;Clin Infect Dis,2002
4. Separate worlds set to collide: smallpox, vaccinia virus vaccination, and human immunodeficiency virus and acquired immunodeficiency syndrome;Amorosa;Clin Infect Dis,2003
5. Ministry of Defence.1998. Available at: http://www.mod.uk/issues/gulfwar/info/medical/bwa/annexes/annexii.htm.