@misc{indiciaea337fbe184d7,
  title = {Spatial variation and evolution of heliospheric sector structure},
  author = {Behannon, K. W. and Burlaga, L. F. and Hoeksema, J. T. and Klein, L. W.},
  year = {1989},
  url = {https://ntrs.nasa.gov/citations/19890041543},
  note = {Source identifier: 19890041543}
}