@misc{indiciae383ad3367021,
  title = {The structure and evolution of coronal holes},
  author = {Timothy, A. F. and Krieger, A. S. and Vaiana, G. S.},
  year = {1975},
  url = {https://ntrs.nasa.gov/citations/19750055992},
  note = {Source identifier: 19750055992}
}