@misc{indiciae5d6fa7b2de95,
  title = {Uncertainty estimates in geomagnetic field modeling},
  author = {Langel, R. A. and Estes, R. H. and Sabaka, T. J.},
  year = {1989},
  url = {https://ntrs.nasa.gov/citations/19890067298},
  note = {Source identifier: 19890067298}
}