Feng Y, Mei S Y, Liu N, Guo R X
Department of Obstetrics and Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450002, China.
Zhonghua Xue Ye Xue Za Zhi. 2018 Mar 14;39(3):242-244. doi: 10.3760/cma.j.issn.0253-2727.2018.03.014.