@misc{indiciae7838a3d73f09,
  title = {Map Showing Construction Materials and Nonmetallic Mineral Resources of Colorado},
  author = {David M. Larrabee and S.E. Clabaugh and W. R. Griffitts and and others},
  year = {1947},
  doi = {10.3133/mb10},
  url = {https://pubs.usgs.gov/publication/mb10},
  note = {Source identifier: mb10}
}