1. Umwelterklärung,1999
2. Vereinfachte Umwelterklärung,2000
3. Heuberger GmbH;Anodisieranstalt,1999
4. Fresner J, Wolf P, Galli M. Effective environmental management by cleaner production. Proceedings of the Symposium “Efficiency through management of resources: Green productivity programs in SME”, EXPO 2000, Hanover, Magdeburg, September 1–5, 2000
5. Cleaner Production as a means for effective environmental management systems;Fresner;Journal of cleaner production,1998