@misc{indiciaef8c0309703ac,
  title = {Geologic map of Knox County, Tennessee},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1972},
  doi = {10.3133/i767b},
  url = {https://pubs.usgs.gov/publication/i767B},
  note = {Source identifier: i767B}
}