1. European Commission. Communication from the commission—energy for the future: renewable sources of energy, White paper for a community strategy and action plan, COM(97)599 final (26/11/1997). See also: 〈http://europa.eu.int/comm/energy/library/599fi_en.pdf〉.
2. Danish Government. Energy 21, the Danish Government's action plan for energy 1996. Copenhagen: Danish Ministry of Environment and Energy, 1996.
3. Australian Government. Securing Australia's energy future—energy white paper, 2004. See also: 〈http://www.dpmc.gov.au/publications/energy_future/docs/energy.pdf〉.
4. U.S Government. National Energy Policy, Report of the National Energy Policy Development Group, May 2001. See also: 〈http://www.whitehouse.gov/energy/National-Energy-Policy.pdf〉.
5. District heating and market economy in Latvia;Lund;Energy,1999