@misc{indiciaedff12426989a,
  title = {United States base map},
  author = {U.S. Geological Survey and U.S. Coast and Geodetic Survey},
  year = {1956},
  doi = {10.3133/70276507},
  url = {https://pubs.usgs.gov/publication/70276507},
  note = {Source identifier: 70276507}
}