@misc{indiciaea34d47d89e18,
  title = {Hydrologic units},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1999},
  doi = {10.3133/7000061},
  url = {https://pubs.usgs.gov/publication/7000061},
  note = {Source identifier: 7000061}
}