@misc{indiciae12467b917ef4,
  title = {Map showing density of dwelling units in the Tungsten quadrangle, Boulder, Gilpin, and Jefferson Counties, Colorado},
  author = {H. R. Covington and D. J. Gable},
  year = {1973},
  doi = {10.3133/i792b},
  url = {https://pubs.usgs.gov/publication/i792B},
  note = {Source identifier: i792B}
}