@misc{indiciae0c322814f37f,
  title = {Preliminary map of the Negaunee 7 1/2 minute quadrangle, Marquette County, Michigan},
  author = {Willard P. Puffett and C.E. Fritts},
  year = {1968},
  doi = {10.3133/ofr68219},
  url = {https://pubs.usgs.gov/publication/ofr68219},
  note = {Source identifier: ofr68219}
}