Referanslar
  1. World Health Organization (WHO), World Health Report, 1998.
  2. World Health Organization (WHO), World Health Report Executive Summary, 1998.
  3. Centers for Diseases Control and Prevention (CDC) Internet Site and published by Chen RT, Hibbs B. Vaccine Safety: Current and Future Challenges, Pediatric Annals 1998: 27 (7): 445-455.
  4. Centers for Disease Control and Prevention (CDC). Epidemiology & Prevention of Vaccine Preventable Diseases, Atkinson W, Hamborsky J, Wolfe S, (eds). 8th ed. Washington,DC:Public Health Foundation. 2004. p. 183, 197.