Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 5,2012, Pages 324-327, doi:10.3760/cma.j.issn.0529-567x.2012.05.002
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 5,2012, Pages 395-397, doi:10.3760/cma.j.issn.0529-567x.2012.05.021
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 5,2012, Pages 387-390, doi:10.3760/cma.j.issn.0529-567x.2012.05.018
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 5,2012, Pages 364-367, doi:10.3760/cma.j.issn.0529-567x.2012.05.011
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 5,2012, Pages 342-346, doi:10.3760/cma.j.issn.0529-567x.2012.05.006