1. Hierarchy: perspectives for Ecological Complexity;Allen,1988
2. Economics, Natural-Resource Scarcity and Development;Barbier,1989
3. Environmental sustainability and cost benefit analysis;Barbier;Environ. Planning A.,1990
4. Sustainable development: is it a useful concept?;Beckerman;Environ. Values,1994
5. Discordant Harmonies: A New Ecology for the Twenty-first Century;Botkin,1990