@misc{indiciaee98434f96393,
  title = {Preliminary bedrock-surface map of the Omaha-Council Bluffs area, Nebraska-Iowa},
  author = {Robert D. Miller},
  year = {1957},
  doi = {10.3133/ofr5773},
  url = {https://pubs.usgs.gov/publication/ofr5773},
  note = {Source identifier: ofr5773}
}