@misc{indiciae41b5286a49c2,
  title = {A user's manual for a method of map scanning and digital editing for thematic map production and data-base construction},
  author = {D. R. Soller and W.R. Stettner and K.J. Lanfear and D. S. Aitken},
  year = {1990},
  doi = {10.3133/cir1054},
  url = {https://pubs.usgs.gov/publication/cir1054},
  note = {Source identifier: cir1054}
}