@misc{indiciaed730fb188852,
  title = {Guidelines for logging, describing, and sampling cores and cuttings of coal and associated rocks at the drill site},
  author = {Robert G. Hobbs},
  year = {1979},
  doi = {10.3133/ofr791522},
  url = {https://pubs.usgs.gov/publication/ofr791522},
  note = {Source identifier: ofr791522}
}