@misc{indiciae1270b4cd9236,
  title = {Program PDP004; CONTUR},
  author = {M.A.M. Donzeau and M. E. Gettings and L.D. North},
  year = {1981},
  doi = {10.3133/ofr81761},
  url = {https://pubs.usgs.gov/publication/ofr81761},
  note = {Source identifier: ofr81761}
}