@misc{indiciae3f36cc97e065,
  title = {Geologic map of the Greenwood quadrangle, Michigan},
  author = {William F. Cannon},
  year = {1971},
  doi = {10.3133/ofr7162},
  url = {https://pubs.usgs.gov/publication/ofr7162},
  note = {Source identifier: ofr7162}
}