Wei Chunyan, Xue Xiang, Zhu Gaixia, Li Mu, Liu Haili, Peng Huixia
Department of Obstetrics and Gynecology, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
Int J Gynaecol Obstet. 2013 Nov;123(2):160-1. doi: 10.1016/j.ijgo.2013.06.017. Epub 2013 Aug 17.