@misc{indiciae562092ac081d,
  title = {A 125 year history of topographic mapping and GIS in the U.S. Geological Survey 1884-2009, part 1: 1884-1980},
  author = {E. Lynn Usery and Dalia Varanka and Michael P. Finn},
  year = {2009},
  url = {https://pubs.usgs.gov/publication/70038929},
  note = {Source identifier: 70038929}
}