@misc{indiciae20620edb948d,
  title = {Film density analyzers for infrared investigations},
  author = {Robert M. Turner and George R. Boynton},
  year = {1968},
  doi = {10.3133/ofr68280},
  url = {https://pubs.usgs.gov/publication/ofr68280},
  note = {Source identifier: ofr68280}
}