@misc{indiciaef9992e1168a8,
  title = {Geologic map of the Scottsbluff 1° x 2° quadrangle, Nebraska and Colorado},
  author = {J. B. Swinehart and R. F. Diffendal},
  year = {1997},
  doi = {10.3133/i2545},
  url = {https://pubs.usgs.gov/publication/i2545},
  note = {Source identifier: i2545}
}