@misc{indiciaec60658f5e1f9,
  title = {Petrography and geology of the igneous rocks of the Highwood Mountains, Montana},
  author = {Louis Valentine Pirsson},
  year = {1905},
  doi = {10.3133/b237},
  url = {https://pubs.usgs.gov/publication/b237},
  note = {Source identifier: b237}
}