@misc{indiciae7016a3725aad,
  title = {Geologic map for land-use planning, Prince Georges County, Maryland},
  author = {J.T. Hack},
  year = {1977},
  doi = {10.3133/i1004},
  url = {https://pubs.usgs.gov/publication/i1004},
  note = {Source identifier: i1004}
}