TY  - RPRT
TI  - Problems and practices in backcountry recreation management: A survey of National Park Service managers
AU  - J. L. Marion
AU  - J.W. Roggenbuck
AU  - R.E. Manning
PY  - 1993
UR  - https://pubs.usgs.gov/publication/5200153
ID  - 5200153
ER  -