@misc{indiciaeb66195d29211,
  title = {Montana areas of oil and gas production},
  author = {Richard F. Mast and D. H. Root and L. P. Williams and W. R. Beeman},
  year = {1994},
  doi = {10.3133/ofr9422c},
  url = {https://pubs.usgs.gov/publication/ofr9422C},
  note = {Source identifier: ofr9422C}
}