CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 1,2009, Pages 16-18, doi:10.3760/cma.j.issn.0529-567x.2009.01.006
CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 1,2009, Pages 62-64, doi:10.3760/cma.j.issn.0529-567x.2009.01.016
CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 1,2009, Pages 50-55, doi:10.3760/cma.j.issn.0529-567x.2009.01.013
CHINESE JOURNAL OF OBSTETRICS AND GYNECOLOGY, Volume 44, Issue 1,2009, Pages 32-37, doi:10.3760/cma.j.issn.0529-567x.2009.01.010