1. Van den Broek R. Sustainability of biomass electricity systems—an assessment of costs, macro-economic and environmental impacts in Nicaragua, Ireland and the Netherlands. Utrecht University, 2000. p. 215.
2. Turkenburg WC. Renewable energy technologies, in World Energy Assessment. In: Goldemberg J, editor. Washington DC: UNDP, 2000. p. 220–72.
3. IPCC. Special Report on Emission Scenarios. Cambridge: Cambridge University Press, 2000.
4. Shell. The evolution of the world's energy system 1860–2060: extracts of a study by Shell International London, 1995.
5. Johansson TB, et al. Renewable fuels and electricity for a growing world economy—defining and achieving the potential, in renewable energy: sources for fuels and electricity. In: Johansson TB, et al., editors. Washington, D.C.: Island Press, 1993. p. 1–71.