@misc{indiciae56c811cf76e0,
  title = {Relation of the carbon/oxygen ratio in coal to igneous intrusions in the Somerset coal field, Colorado},
  author = {John R. Dyni and David L. Gaskill},
  year = {1980},
  doi = {10.3133/b1477a},
  url = {https://pubs.usgs.gov/publication/b1477A},
  note = {Source identifier: b1477A}
}