@misc{indiciae9533e52c0e78,
  title = {Progress of surveys in the Anthracite Ridge District},
  author = {Ralph Webster Richards and Gerald Ashley Waring},
  year = {1933},
  doi = {10.3133/b849a},
  url = {https://pubs.usgs.gov/publication/b849A},
  note = {Source identifier: b849A}
}