@misc{indiciae77ca75490166,
  title = {Hydrogeology of the basal confining unit of the carbonate aquifer system in the Midwestern Basins and Arches region of Indiana, Ohio, Michigan, and Illinois},
  author = {George D. Casey},
  year = {1992},
  doi = {10.3133/ofr92489},
  url = {https://pubs.usgs.gov/publication/ofr92489},
  note = {Source identifier: ofr92489}
}