@misc{indiciae9fc718172f5f,
  title = {Composite magnetic anomaly map of the United States: Part A: Conterminous United States},
  author = {Isidore Zietz},
  year = {1982},
  doi = {10.3133/gp954a},
  url = {https://pubs.usgs.gov/publication/gp954A},
  note = {Source identifier: gp954A}
}