Venous phase in spinal cord angiography.

@article{Fried1971VenousPI,
  title={Venous phase in spinal cord angiography.},
  author={L C Fried and John L. Doppman and Giovanni Di Chiro},
  journal={Acta radiologica: diagnosis},
  year={1971},
  volume={11 4},
  pages={393-401}
}