@misc{indiciae2e6e9359d007,
  title = {Reconnaissance map showing relative amounts of soil and bedrock in the mountainous part of the Ralston Buttes quadrangle and adjoining areas to the east and west in Jefferson County, Colorado},
  author = {K. L. Pierce and P. W. Schmidt},
  year = {1975},
  doi = {10.3133/mf689},
  url = {https://pubs.usgs.gov/publication/mf689},
  note = {Source identifier: mf689}
}