@misc{indiciae31e6e9d23786,
  title = {Entrenchment and widening of the upper San Pedro River, Arizona},
  author = {Richard Hereford},
  year = {1993},
  doi = {10.1130/spe282-p1},
  url = {https://pubs.usgs.gov/publication/70207343},
  note = {Source identifier: 70207343}
}