@misc{indiciaef188092ae181,
  title = {Main field and recent secular variation.},
  author = {L.R. Alldredge},
  year = {2010},
  doi = {10.1029/rg021i003p00599},
  url = {https://pubs.usgs.gov/publication/70012069},
  note = {Source identifier: 70012069}
}