@article{d. zhang2011value,
  title={Sonographic value in diagnosis of hemorrhagic ovarian cysts},
  author={z. ding,d. zhang,w. ying,j. wang},
  journal={European Journal of Gynaecological Oncology},
  volume={31},
  number={1},
  pages={87--89},
  doi = {10.12892/ejgo20100187},
  year={2011}
}