@misc{indiciae1ca18a853673,
  title = {Travel time variation on backcountry trails},
  author = {J. W. van Wagtendonk and J.M. Benedict},
  year = {2018},
  doi = {10.1080/00222216.1980.11969429},
  url = {https://pubs.usgs.gov/publication/1007466},
  note = {Source identifier: 1007466}
}