Strine Tara W, Mokdad Ali H, Barker Lawrence E, Groom Amy V, Singleton Rosalyn, Wilkins Craig S, Chu Susan Y
National Immunization Program, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA.
Am J Public Health. 2003 Dec;93(12):2046-9. doi: 10.2105/ajph.93.12.2046.