@misc{indiciaeeb94bfb62999,
  title = {Geology and fuel resources of the southern part of the Oklahoma coal field. Part 2, The Lehigh district, Coal, Atoka, and Pittsburg Counties},
  author = {M. M. Knechtel},
  year = {1937},
  doi = {10.3133/b874b},
  url = {https://pubs.usgs.gov/publication/b874B},
  note = {Source identifier: b874B}
}