Chinese Journal of Perinatal Medicine, Volume 14, Issue 11,2011, Pages 666-669, doi:10.3760/cma.j.issn.1007-9408.2011.11.006
Chinese Journal of Perinatal Medicine, Volume 14, Issue 11,2011, Pages 682-687, doi:10.3760/cma.j.issn.1007-9408.2011.11.009
Chinese Journal of Perinatal Medicine, Volume 14, Issue 11,2011, Pages 676-681, doi:10.3760/cma.j.issn.1007-9408.2011.11.008
Chinese Journal of Perinatal Medicine, Volume 14, Issue 11,2011, Pages 689-692, doi:10.3760/cma.j.issn.1007-9408.2011.11.011