1. Recommended childhood immunization schedule—United States, 1999.;CDC;MMWR.,1999
2. Recommended childhood immunization schedule—United States, January–December 1999.;American Academy of Pediatrics, Committee on Infectious Diseases;Pediatrics.,1999
3. Food and Drug Administration approval of use of diphtheria and tetanus toxoids and acellular pertussis vaccine.;CDC;MMWR.,1991
4. Food and Drug Administration approval of a second diphtheria and tetanus toxoids and acellular pertussis vaccine.;CDC;MMWR.,1992