1. The recreation opportunity spectrum – a challenge to Canadian foresters;Angelo;The Forestry Chronicle,1981
2. A new planning tool: the tourism opportunity spectrum;Butler;Journal of Tourism Studies,1991
3. The use of recreation planning tools in U.S. Forest Service NEPA assessments;Cerveny;Environmental Management,2011
4. The Recreation Opportunity Spectrum: A Framework for Planning, Management, and Research;Clark,1979
5. South Carolina’s Timber, 1968. U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station, Asheville, NC;Knight,1969