1. BERR (2007a) Digest of UK Energy Statistics (DUKES) 2007. Department of Business and Regulatory Reform (BERR). World Wide Web Address: http://stats.berr.gov.uk/energystats/dukes07.pdf .
2. BERR (2007b) Department of Business, Environment and Regulatory Reform (BERR) website for production statistics. World Wide Web Addresses: http://www.og.berr.gov.uk/information/statistics.htm and http://www.og.berr.gov.uk/pprs/full_production.htm .
3. BGS (2004) Memorandum by British Geological Survey to the House of Lords Select Committee on European Union. Gas: Liberalised Markets and Security of Supply. House of Lords, European Union Committee 17th Report of Session 2003–2004, 87–90. World Wide Web Address: http://www.publications.parliament.uk/pa/ld200304/ldselect/ldeucom/105/105we04.htm .
4. Canatxx (2003) Proposed Natural Gas Storage Facility, Preesall Saltfield. 2003. Canatxx Gas Storage Limited, Non-Technical Summary of the Environmental Statement. World Wide Web Address: http://www.lancashire.gov.uk/environment/documents/DevC/Extra/02.04.1415nts.pdf .
5. DTI (2006) The Energy Challenge: Energy Review Report. Department of Trade and Industry, July 2006. World Wide Web Address: http://www.berr.gov.uk/files/file31890.pdf .