@misc{indiciaed4206b5234c5,
  title = {Recent developments in the Aspen district, Colorado},
  author = {Adolph Knopf},
  year = {1926},
  doi = {10.3133/b785a},
  url = {https://pubs.usgs.gov/publication/b785A},
  note = {Source identifier: b785A}
}