@misc{indiciae215e1765c8ca,
  title = {Magnetic models for the United States for 1985},
  author = {Norman W. Peddie and Audronis K. Zunde},
  year = {1990},
  doi = {10.3133/cir1039},
  url = {https://pubs.usgs.gov/publication/cir1039},
  note = {Source identifier: cir1039}
}