@misc{indiciaecb14274913a3,
  title = {Current coal research-coal resource studies in the United States during 1950},
  author = {P. Averitt},
  year = {1951},
  doi = {10.2113/gsecongeo.46.8.836},
  url = {https://pubs.usgs.gov/publication/70221617},
  note = {Source identifier: 70221617}
}