@misc{indiciae5b64a2010be4,
  title = {The magnetic field of the earth, 1980 magnetic declination},
  author = {E. B. Fabiano and N.W. Peddie and A.K. Zunde},
  year = {1983},
  doi = {10.3133/i1457},
  url = {https://pubs.usgs.gov/publication/i1457},
  note = {Source identifier: i1457}
}