@misc{indiciae6a3ece88e16f,
  title = {Frequency of debris flows in Grand Canyon},
  author = {Robert H. Webb and Peter G. Griffiths and Tillie A. Klearman},
  year = {2003},
  doi = {10.3133/fs06503},
  url = {https://pubs.usgs.gov/publication/fs06503},
  note = {Source identifier: fs06503}
}