@misc{indiciae33b8099cd7b4,
  title = {Problems and practices in backcountry recreation management: A survey of National Park Service managers},
  author = {J. L. Marion and J.W. Roggenbuck and R.E. Manning},
  year = {1993},
  url = {https://pubs.usgs.gov/publication/5200153},
  note = {Source identifier: 5200153}
}