@misc{indiciae7d84e0a81d52,
  title = {Magnetospheric chorus - Occurrence patterns and normalized frequency},
  author = {Burtis, W. J. and Helliwell, R. A.},
  year = {1976},
  url = {https://ntrs.nasa.gov/citations/19770033386},
  note = {Source identifier: 19770033386}
}