CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 7,2009, Pages 504-508, doi:10.3760/cma.j.issn.0529-567x.2009.07.007
CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 7,2009, Pages 529-532, doi:10.3760/cma.j.issn.0529-567x.2009.07.012
CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 7,2009, Pages 551-553, doi:10.3760/cma.j.issn.0529-567x.2009.07.018
CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 7,2009, Pages 509-513, doi:10.3760/cma.j.issn.0529-567x.2009.07.008