1. Recommended childhood immunization schedule—United States, 2001;MMWR Morb Mortal Wkly Rep,2001
2. General recommendations on immunization;MMWR Morb Mortal Wkly Rep,2002
3. Timeliness of childhood immunizations;Luman;Pediatrics,2002
4. National, state, and urban-area vaccination-coverage levels among children aged 19–35 months, United States, 1999;Luman;Am J Prev Med,2001
5. The need for surveillance of delay in age-appropriate immunization;Dombkowski;Am J Prev Med,2002