@misc{indiciae705ba5a7a0bf,
  title = {Topographic mapping: A challenging future},
  author = {U.S. Geological Survey},
  year = {1964},
  doi = {10.3133/70170888},
  url = {https://pubs.usgs.gov/publication/70170888},
  note = {Source identifier: 70170888}
}