@misc{indiciae0fba35c26d50,
  title = {The outer structure of the Crab Nebula},
  author = {Chevalier, R. A. and Gull, T. R.},
  year = {1975},
  url = {https://ntrs.nasa.gov/citations/19750060840},
  note = {Source identifier: 19750060840}
}