Ying Hao, Duan Tao, Bao Yi-Rong, Song Yue-Hua, Wang De-Fen
Department of Obstetrics, Shanghai First Maternity and Infant Health Hospital, Tongji University, Shanghai, China.
Int J Gynaecol Obstet. 2010 Mar;108(3):247-8. doi: 10.1016/j.ijgo.2009.10.006. Epub 2009 Nov 25.