@misc{indiciaef97a58ca344a,
  title = {Monitoring trail conditions: New methodological considerations},
  author = {Jeffrey L. Marion and Yu-Fai Leung and Sanjay K. Nepal},
  year = {2006},
  url = {https://pubs.usgs.gov/publication/5224679},
  note = {Source identifier: 5224679}
}