@misc{indiciae7c143cbc9f28,
  title = {Sources of data, procedures, and bibliography for coal resource investigation of western Maryland},
  author = {Paul C. Lyons and Edwin F. Jacobsen},
  year = {1981},
  doi = {10.3133/ofr81739},
  url = {https://pubs.usgs.gov/publication/ofr81739},
  note = {Source identifier: ofr81739}
}