@misc{indiciae4c70268aa3f9,
  title = {Geologic map showing configuration of the bedrock surface, North Platte 1 degree by 2 degrees Quadrangle, Nebraska},
  author = {R. F. Diffendal},
  year = {1991},
  doi = {10.3133/i2277},
  url = {https://pubs.usgs.gov/publication/i2277},
  note = {Source identifier: i2277}
}