@article{k. niwa2007endodermal,
  title={Primary endodermal sinus tumor of the vulva in a 52-year-old woman with long-term survival: a case report},
  author={k. niwa,k. onogi,y. wu,h. mori,t. tamaya},
  journal={European Journal of Gynaecological Oncology},
  volume={28},
  number={6},
  pages={506--508},
  doi = {10.12892/ejgo200706506},
  year={2007}
}