@misc{indiciae257ab2747d64,
  title = {Holocene geomagnetic secular variation in the western United States: implications for the global geomagnetic field},
  author = {Duane E. Champion},
  year = {1980},
  doi = {10.3133/ofr80824},
  url = {https://pubs.usgs.gov/publication/ofr80824},
  note = {Source identifier: ofr80824}
}