@misc{indiciae806663e3c6ca,
  title = {International geomagnetic reference field 1980},
  author = {N.W. Peddie},
  year = {1982},
  doi = {10.1007/bf00879437},
  url = {https://pubs.usgs.gov/publication/70011832},
  note = {Source identifier: 70011832}
}