@misc{indiciaed21c0649cc83,
  title = {The southern extension of the Milk River coal field, Chouteau County, Montana. The Livingston and Trail Creek coal fields, Park, Gallatin, and Sweet Counties, Montana. The Electric coal field, Park County, Montana},
  author = {L.J. Pepperberg and W. R. Calvert},
  year = {1912},
  doi = {10.3133/b471e},
  url = {https://pubs.usgs.gov/publication/b471E},
  note = {Source identifier: b471E}
}