Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 2,2012, Pages 105-109, doi:10.3760/cma.j.issn.0529-567x.2012.02.006
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 2,2012, Pages 121-124, doi:10.3760/cma.j.issn.0529-567x.2012.02.009
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 2,2012, Pages 115-120, doi:10.3760/cma.j.issn.0529-567x.2012.02.008
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 2,2012, Pages 150-152, doi:10.3760/cma.j.issn.0529-567x.2012.02.018
Chinese Journal of Obstetrics and Gynecology, Volume 47, Issue 2,2012, Pages 90-95, doi:10.3760/cma.j.issn.0529-567x.2012.02.003