1. EC. European energy to 2020: a scenario approach. Directorate General for Energy (DG XVII), Luxembourg: 1996.
2. EC. Energy for the future: renewable sources of energy. White Paper for a Community Strategy and Action Plan. COM (97) 599 final (26/11/97), Brussels, http://europa.eu.int/en/comm/dg17/599fi_en.thm#refI.
3. Berdowskii J, Gager M, Raberger B, Ritter M, Visschedijk A. Overview of national programmes to reduce greenhouse gas emissions. European Topic Centre on Air Emission, Topic Report No. 8/1999, EEA, Copenhagen: 1999.
4. Fischer G, van Velthuizen HT, Shah MM, Nachtergaele FO. Global agro-ecological assessment for agriculture in the 21st Century: methodology and results. International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria, Report RR-02-002, 2002.
5. Fischer G, van Velthuizen HT, Prieler S. Assessment of potential productivity of tree species in China, Mongolia and the former Soviet Union: methodology and results. IIASA, Laxenburg, Austria, Report IR-01-015, 2001.