1. Anon, 2001. European Climate Change Programme, European Commission, 〈http://ec.europa.eu/environment/climat/eccpreport.htm〉 (accessed 28/5/8).
2. AUDI AG, 2003. Audi in Fakten und Zahlen 2003 [Audi in facts and Figs. 2003], AUDI AG Finanzanalytik und Publizität I/FF-12 85045, Ingolstadt Deutschland: 〈http://www.audi.com/etc/medialib/cms4imp/audi2/company/financial_information/pdf.Par.0178.File.pdf〉 (accessed 10 April 2008).
3. Barrett, M., 2007a. Low Emission Energy Scenarios for the European Union: ISBN: 978-91-620-5785-5 〈http://www.naturvardsverket.se/Documents/bokhandeln/620-5785-5.htm〉 (accessed 10 April 2008).
4. Barrett, M., 2007b. A renewable electricity system for the UK. In: Boyle, G. (Ed.), Renewable Energy and the Grid: The Challenge of Variability. Earthscan, London. ISBN-13: 978-1-84407-418-1 (hardback).
5. 40% House;Boardman,2005