@misc{indiciae31864ea13423,
  title = {Reconnaissance map showing relative amounts of soil and bedrock in the mountainous part of the Lyons Quadrangle, Boulder County, Colorado},
  author = {P. W. Schmidt},
  year = {1978},
  doi = {10.3133/mf999},
  url = {https://pubs.usgs.gov/publication/mf999},
  note = {Source identifier: mf999}
}