4Feng XL,Xu L,Guo Y,et al. Factors influencing rising caesareansection rates in China between 1988 and 2008[J]. Bull World Health Organ,2012,90(1 ) :30-39.
5Mazzoni A,Ahhabe F,Liu NH,et al. Women's preference for caesare- an section: A systematic review and meta-analysis of observational studies[J]. BJOG,2011,118(4) : 391-399.