@misc{indiciaedc1c92e16779,
  title = {Aeromagnetic map of the Perch Lake quadrangle, Houghton, Baraga, and Iron Counties, Michigan},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1967},
  doi = {10.3133/gp600},
  url = {https://pubs.usgs.gov/publication/gp600},
  note = {Source identifier: gp600}
}