@misc{indiciae39baea78e6a9,
  title = {Digital line graphs from 1:2,000,000-scale maps},
  author = {Michael A. Domaratz and C.A. Hallam and W.E. Schmidt and H.W. Calkins},
  year = {1983},
  doi = {10.3133/cir895d},
  url = {https://pubs.usgs.gov/publication/cir895D},
  note = {Source identifier: cir895D}
}