@misc{indiciaedf1215bbdd51,
  title = {Mineral resources of the Indian Peaks study area, Boulder and Grand Counties, Colorado},
  author = {Robert Carl Pearson and Charles N. Speltz and Gordon Johnson},
  year = {1975},
  doi = {10.3133/ofr75500},
  url = {https://pubs.usgs.gov/publication/ofr75500},
  note = {Source identifier: ofr75500}
}