@misc{indiciae527840bc3b5c,
  title = {Aeromagnetic map of the eastern part of the Northern Peninsula of Michigan},
  author = {W.F. Cannon and A.E. Fenichel},
  year = {1981},
  doi = {10.3133/gp947},
  url = {https://pubs.usgs.gov/publication/gp947},
  note = {Source identifier: gp947}
}