@misc{indiciae17d8da582924,
  title = {Coronal holes.},
  author = {Altschuler, M. D. and Trotter, D. E. and Orrall, F. Q.},
  year = {1972},
  url = {https://ntrs.nasa.gov/citations/19730032233},
  note = {Source identifier: 19730032233}
}