@misc{indiciae09dfb1544f6f,
  title = {Photogeologic procedures in geologic interpretation and mapping},
  author = {Richard G. Ray},
  year = {1956},
  doi = {10.3133/b1043a},
  url = {https://pubs.usgs.gov/publication/b1043A},
  note = {Source identifier: b1043A}
}