1. A history of immunization;Parish,1965
2. Smallpox and its eradication;Fenner,1988
3. Annual Report 2005/06,2007
4. Direct and indirect effects of routine vaccination of children with 7-valent pneumococcal conjugate vaccine on incidence of invasive pneumococcal disease, United States, 1998–2003;MMWR,2005
5. Delayed onset and diminished magnitude of rotavirus activity – United States, November 2007–May 2008;MMWR,2008