@misc{indiciae1cf78b48a1a2,
  title = {Geologic map of the Greenland and Rockland quadrangles, Ontonagan County, Michigan},
  author = {Jesse W. Whitlow},
  year = {1972},
  doi = {10.3133/ofr741123},
  url = {https://pubs.usgs.gov/publication/ofr741123},
  note = {Source identifier: ofr741123}
}