@misc{indiciae4aace00e0a2c,
  title = {Low-cost computer classification of land cover in the Portland area, Oregon, by signature extension techniques},
  author = {Leonard Gaydos},
  year = {1978},
  doi = {10.3133/ofr78186},
  url = {https://pubs.usgs.gov/publication/ofr78186},
  note = {Source identifier: ofr78186}
}