@misc{indiciaeb77813ca911a,
  title = {Phosphate rock near Maxville, Philipsburg, and Avon, Montana},
  author = {J. T. Pardee},
  year = {1936},
  doi = {10.3133/b847d},
  url = {https://pubs.usgs.gov/publication/b847D},
  note = {Source identifier: b847D}
}