@misc{indiciaeae196d4e9055,
  title = {The interpretation of topographic maps},
  author = {Rollin D. Salisbury and Wallace Walter Atwood},
  year = {1908},
  doi = {10.3133/pp60},
  url = {https://pubs.usgs.gov/publication/pp60},
  note = {Source identifier: pp60}
}