@misc{indiciae15918a516ea3,
  title = {Atmospheric density variations at 140 km deduced from precise satellite radar track ing data},
  author = {De Vries, L. L. and Schusterman, L. and Bruce, R. W.},
  year = {1971},
  url = {https://ntrs.nasa.gov/citations/19710024828},
  note = {Source identifier: 19710024828}
}