5Ross, John, Edward Abel, et al. Plateaus during the rise of contracetive prevalence[J]. International family planning perspectives, 2004, 30(1):39-44.
6Rana Rao,Saumya,Marlina Lacuesta,et al. The Link between quality of careand contraceptive use[J]. International Family Planning Perspectives, 2003, 29(2):76-83.
7Peason TA, Mensah GA, Korovesis SD. Chinatoupgradeits for IUD of technology[J].Progressin Reproductive Health Research (SHR) ,2002,60:4.