Variations in the Profiles of Vascular-Related Factors Among Different Sub-Types of Polycystic Ovarian Syndrome in Northern China oleh Mei-mei Liu, Xiu-hui Chen, Xiu-min Lu, Fang-fang Wang, Chao Wang, Yu Liu, Pei-ling Li, Bo-tao Du, Sha Liang, Pi-dong Gong, Yu-xin Wang