@misc{indiciae6c2fb896297e,
  title = {Preliminary soil classification map of southwestern U.S. and Mexico from space photography},
  author = {Roger B. Morrison},
  year = {1968},
  doi = {10.3133/ofr68189},
  url = {https://pubs.usgs.gov/publication/ofr68189},
  note = {Source identifier: ofr68189}
}