1. The Economic Value of Ecosystems: 1—Tropical Wetlands;Barbier,1989
2. USING DIRECT QUESTIONING TO VALUE THE EXISTENCE BENEFITS OF PRESERVED NATURAL AREAS
3. Economies of Protected Areas: A New Look at Benefits and Costs;Dixon,1990
4. Logging versus fisheries and tourism in Palawan;Hodgson,1988
5. Technical Report on Coastal erosion in Kiribati;Howarth,1982