@misc{indiciae70bedc78dfac,
  title = {Geology and petroleum potential, Central Montana Province},
  author = {E. K. Maughan},
  year = {1989},
  doi = {10.3133/ofr88450n},
  url = {https://pubs.usgs.gov/publication/ofr88450N},
  note = {Source identifier: ofr88450N}
}