@misc{indiciaeaa885641f935,
  title = {Bedrock-surface altitude in the midwestern basins and arches region of Indiana, Ohio, Michigan, and Illinois},
  author = {Danny W. Bunner},
  year = {1993},
  doi = {10.3133/wri934050},
  url = {https://pubs.usgs.gov/publication/wri934050},
  note = {Source identifier: wri934050}
}