9He H, Blum R W. Prevalence of unintended pregnancy and its associated factors among sexually active never-married youth in Shanghai [J]. Journal of Paediatrics and Child Health, 2013,49 (11) :912-918. :1863.
10Huang Y M, Merkatz R, Kang J Z. Postpartum unintended pregnancy and contraception practice among rural-to-urban migrant women in Shanghai[J],Contraception,2012, 86 ( 6 ) : 731,738.
