@misc{indiciae8d36ac2fc188,
  title = {Contributions to Precambrian geology of Lake Superior region},
  author = {Paul K. Sims and Lorna M.H. Carter},
  year = {1990},
  doi = {10.3133/b1904},
  url = {https://pubs.usgs.gov/publication/b1904},
  note = {Source identifier: b1904}
}