@misc{indiciae23a35cb93d7c,
  title = {Bedrock geology of the Louisville quadrangle, Colorado},
  author = {Frank Darwyn Spencer},
  year = {1961},
  doi = {10.3133/gq151},
  url = {https://pubs.usgs.gov/publication/gq151},
  note = {Source identifier: gq151}
}