@misc{indiciae5a818a3123a3,
  title = {Hydrologic Unit Map – 1988, states of Massachusetts, Rhode Island and Connecticut},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1988},
  doi = {10.3133/hu21},
  url = {https://pubs.usgs.gov/publication/hu21},
  note = {Source identifier: hu21}
}