@misc{indiciae77c0765914d2,
  title = {Hydrologic Unit Map -- 1974, State of Missouri},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1977},
  doi = {10.3133/hu25},
  url = {https://pubs.usgs.gov/publication/hu25},
  note = {Source identifier: hu25}
}