@misc{indiciaea7725def405a,
  title = {Pre-Quaternary geologic and magnetic map and sections of part of the eastern Gogebic Iron Range, Michigan},
  author = {W. C. Prinz and J.A. Hallbert},
  year = {1967},
  doi = {10.3133/i497},
  url = {https://pubs.usgs.gov/publication/i497},
  note = {Source identifier: i497}
}