1. EN ISO 14040:2009-11 (2009) Environmental management–life cycle assessment–principles and framework
2. EN ISO 14044:2006-10 (2006) Environmental management–life cycle assessment–requirements and guidelines
3. European Commission (2010) Joint Research Centre, Institute for Environment and Sustainability: International Reference Life Cycle Data System (ILCD) Handbook. Specific guide for life cycle inventory data sets. First edition March 2010. EUR 24709 EN. Luxembourg. Publications Office of the European Union
4. GaBi 6 (2012) GaBi 6 dataset documentation for the software-system and databases, LBP, University of Stuttgart and thinkstep AG, Leinfelden-Echterdingen; 2012 ( http://documentation.gabi-software.com/ )
5. International Energy Agency (IEA) (2013) World energy statistics; Paris, France; 2013