@misc{indiciae9a060f55b2df,
  title = {USGS international activities in coal resources},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1999},
  doi = {10.3133/fs11999},
  url = {https://pubs.usgs.gov/publication/fs11999},
  note = {Source identifier: fs11999}
}