@misc{indiciae2d95ec72f9a6,
  title = {Variations in electric fields from polar orbiting satellites},
  author = {Heppner, J. P. and Maynard, N. C.},
  year = {1969},
  url = {https://ntrs.nasa.gov/citations/19690027648},
  note = {Source identifier: 19690027648}
}