@misc{indiciae6e5d0a987b3b,
  title = {An automatic, quasi-absolute, geomagnetic calibration system},
  author = {E.A. Sauter},
  year = {1991},
  doi = {10.3133/ofr91350},
  url = {https://pubs.usgs.gov/publication/ofr91350},
  note = {Source identifier: ofr91350}
}