1. Frischknecht, R. et al. (1994): Ökoinventare für Energiesysteme, Bundesamt für Energiewirtschaft Zürich.
2. Heijungs, R. (1992a): Environmental Life Cycle Assessment of Products, Guide — October 1992. Centre of Environmental Science, Leiden
3. Heijungs, R. (1992b): Environmental Life Cycle Assessment of Products, Backgrounds — October 1992. Centre of Environmental Science, Leiden
4. Heijungs, R. (1994): A generic method for the identification of options for cleaner products. In: Ecological Economics 10, p. 69-81.
5. 3. Huppes, G., Schneider, F. (eds.), (1994): Proceedings of the European Workshop on Allocation in LCA at the Centre of Environmental Science