Bibliografía (9 obras)
Global forests
1991
Demand for an annual pass to Costa Rica's national parks
1990
International travel by U.S. conservation groups and professional societies
1988
A survey of return visits to Costa Rica by OTS participants and associates
1987
Nature travel in the tropics
Tropical tourism as economic activity
Nature-oriented tourism in Costa Rica and Ecuador
1986
Private enterprise initiatives for international forestry development
1984
Choice of technology in forestry
1981
