@misc{indiciae81040e5f3040,
  title = {Aeromagnetic map of parts of Marquette, Dickinson, Baraga, Alger, and Schoolcraft Counties, Michigan},
  author = {James R. Balsley and F.A. Petrafeso},
  year = {1964},
  doi = {10.3133/ofr647},
  url = {https://pubs.usgs.gov/publication/ofr647},
  note = {Source identifier: ofr647}
}