@article{fei1997study,
  title={The study of a frameless stereotactic localization method using DSA},
  author={Fei, Baowei and Zhuang, Tiange},
  journal={Zhongguo yi liao qi xie za zhi= Chinese journal of medical instrumentation},
  volume={21},
  number={4},
  pages={207--210},
  year={1997}
}