@misc{indiciaef1ca1fbd5b10,
  title = {Coal resources of Michigan},
  author = {George Vincent Cohee and R.N. Burns and Andrew Brown and R.A. Brant and Dorothy Wright},
  year = {1950},
  doi = {10.3133/cir77},
  url = {https://pubs.usgs.gov/publication/cir77},
  note = {Source identifier: cir77}
}