Chinese Journal of Perinatal Medicine, Volume 15, Issue 4,2012, Pages 217-221, doi:10.3760/cma.j.issn.1007-9408.2012.04.007
Chinese Journal of Perinatal Medicine, Volume 15, Issue 4,2012, Pages 228-233, doi:10.3760/cma.j.issn.1007-9408.2012.04.009
Chinese Journal of Perinatal Medicine, Volume 15, Issue 4,2012, Pages 222-227, doi:10.3760/cma.j.issn.1007-9408.2012.04.008
Chinese Journal of Perinatal Medicine, Volume 15, Issue 4,2012, Pages 246-249, doi:10.3760/cma.j.issn.1007-9408.2012.04.014
Chinese Journal of Perinatal Medicine, Volume 15, Issue 4,2012, Pages 206-210, doi:10.3760/cma.j.issn.1007-9408.2012.04.005