National poliomyelitis immunization days--People's Republic of China, 1993.
D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003906:Developing Countries; D005260:Female; D006801:Humans; D017589:Immunization Programs; D015994:Incidence; D007223:Infant; D008297:Male; D011051:Poliomyelitis / Q000453:epidemiology / Q000517:prevention & control*; D011055:Poliovirus Vaccine, Oral / Q000008:administration & dosage*
D011055:Poliovirus Vaccine, Oral