@article{x.x. chen2020factors,
  title={Prognostic factors for types I and II epithelial
ovarian cancer in the elderly},
  author={x.z. cheng,z. zhou, m.y. yang,y.l. cai,f. deng,x.x. chen},
  journal={European Journal of Gynaecological Oncology},
  volume={41},
  number={1},
  pages={7--15},
  doi = {10.31083/j.ejgo.2020.01.4826},
  year={2020}
}