1. 1998. The Political Influence of Global NGOs, Case Studies on the Climate and Biodiversity Conventions. International: Utrecht.
2. (eds). 2001. Non-State Actors in International Relations. Ashgate: Aldershot.
3. Assessing Political Influence in Complex Decision-Making: An Instrument Based on Triangulation
4. 1991. Ozone Diplomacy: New Directions in Safeguarding the Planet. Harvard University Press: Cambridge.
5. 1994. The Earth Brokers. Power, Politics and World Development. Routledge: London.