1. EN ISO 14040
, International Organisation for Standardisation, Geneva, 2006
2. EN ISO 14044
, International Organisation for Standardisation, Geneva, 2006
3. Life cycle assessment (LCA) applied to the process industry: a review
4. Life Cycle Assessment: Past, Present, and Future
5. Deutsches Institut für Normung e.V., Beuth Verlag GmbH, Berlin, 2006