Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 1,2012, Pages 67-70, doi:10.3760/cma.j.issn.0529-567x.2012.01.020
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 1,2012, Pages 19-23, doi:10.3760/cma.j.issn.0529-567x.2012.01.006
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 1,2012, Pages 24-28, doi:10.3760/cma.j.issn.0529-567x.2012.01.007
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 1,2012, Pages 29-32, doi:10.3760/cma.j.issn.0529-567x.2012.01.008
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 1,2012, Pages 45-47, doi:10.3760/cma.j.issn.0529-567x.2012.01.011