@misc{indiciae49a95af3b06c,
  title = {United States base map},
  author = {U.S. Geological Survey and U.S. Coast and Geodetic Survey},
  year = {1933},
  doi = {10.3133/70276489},
  url = {https://pubs.usgs.gov/publication/70276489},
  note = {Source identifier: 70276489}
}