@misc{indiciaea13ad1c9d420,
  title = {A model of geomagnetic secular variation for 1980-1983},
  author = {N.W. Peddie and A.K. Zunde},
  year = {1987},
  doi = {10.1016/0031-9201(87)90155-5},
  url = {https://pubs.usgs.gov/publication/70014179},
  note = {Source identifier: 70014179}
}