@misc{indiciae64881962cdca,
  title = {A preliminary investigation of enhancement techniques using infrared ektachrome processed as a negative and a positve},
  author = {J. Ronald Eyton},
  year = {1971},
  doi = {10.3133/ofr7199},
  url = {https://pubs.usgs.gov/publication/ofr7199},
  note = {Source identifier: ofr7199}
}