CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 12,2009, Pages 915-919, doi:10.3760/cma.j.issn.0529-567x.2009.12.008
CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 12,2009, Pages 892-897, doi:10.3760/cma.j.issn.0529-567x.2009.12.004
CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 12,2009, Pages 947-949, doi:10.3760/cma.j.issn.0529-567x.2009.12.016
CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 12,2009, Pages 881-882, doi:10.3760/cma.j.issn.0529-567x.2009.12.001