1PRCMPH. National epidemiological survey of dental caries and periodontal disease among school children. Beijing: PRC Ministry of Public Health, People's Heath Publishing Bureau, 1987.
2PRCMPH. Second National epidemiological survey of oral health. Beijing: PRC Ministry of Public Health, People's Heath Publishing Bureau, 1999.
3Petersen PE, Guang LX. Dental caries prevalence in a group of schoolchildren in Wuhan City, PR China 1993 [ J ]. Community Dent Oral Epidemiot, 1994,22:465.
4Wang ZJ,Shen Y,Schwartz E. Dental caries prevalence of 6-14- year - old children in Guangdong, China [ J ]. Community Dent Oral Epidemiol 1994.22:340.
5Douglass JM, Wei Y, Zhang BX, et al. Caries prevalence and pattern in 3 - 6 - year - old Beijing Children [ J ]. Community Dent Oral Epidemiol, 1995,23:340.