@misc{indiciaefa99c5f361f6,
  title = {Interplanetary sector boundaries, 1971 - 1973},
  author = {Klein, L. and Burlaga, L. F.},
  year = {1979},
  url = {https://ntrs.nasa.gov/citations/19790025962},
  note = {Source identifier: 19790025962}
}