@misc{indiciaecf17c99340e2,
  title = {The National Coal Resources Data System: A status report},
  author = {M. Devereaux Carter and Antoinette L. Medlin and Kathleen K. Krohn},
  year = {1981},
  doi = {10.1130/0016-7606(1981)92<563:tncrds>2.0.co;2},
  url = {https://pubs.usgs.gov/publication/70188934},
  note = {Source identifier: 70188934}
}