@misc{indiciae23321edd386d,
  title = {Map showing distribution, composition, and age of Late Cenozoic volcanic centers in Idaho, western Montana, west-central South Dakota, and northwestern Wyoming},
  author = {R. G. Luedke and R. L. Smith},
  year = {1983},
  doi = {10.3133/i1091e},
  url = {https://pubs.usgs.gov/publication/i1091E},
  note = {Source identifier: i1091E}
}