@misc{indiciaea7f42e309851,
  title = {Stratigraphic sequence form manual: guide for entering stratigraphic data into the National Coal Resource Data System (NCRDS)},
  author = {M. Devereux Carter and A.L. Medlin and M.A. Carey and K.K. Krohn},
  year = {1981},
  doi = {10.3133/ofr81562},
  url = {https://pubs.usgs.gov/publication/ofr81562},
  note = {Source identifier: ofr81562}
}