@misc{indiciaee29e26ec21f6,
  title = {Geology and ground-water resources of the Big Sandy Creek Valley, Lincoln, Cheyenne, and Kiowa Counties, Colorado},
  author = {Donald L. Coffin and Clarence Albert Horr},
  year = {1967},
  doi = {10.3133/wsp1843},
  url = {https://pubs.usgs.gov/publication/wsp1843},
  note = {Source identifier: wsp1843}
}