@misc{indiciaebdec6c9b3de9,
  title = {Analysis of ionospheric refraction error corrections for GRARR systems},
  author = {Mallinckrodt, A. J. and Parker, H. C. and Berbert, J. H.},
  year = {1971},
  url = {https://ntrs.nasa.gov/citations/19740010911},
  note = {Source identifier: 19740010911}
}