1. Situation of agricultural recycling of sludge from wastewater treatment plants in Europe;ADEME,1999
2. ISO 14040. Environmental management – life cycle assessment – principles and framework,1997
3. ISO 14041. Environmental management – life cycle assessment – goal and scope definition and inventory analysis,1998
4. ISO 14042. Environmental management – life cycle assessment – life cycle impact assessment,2000
5. Guinée JB. Handbook on life cycle assessment, operational guide to the ISO standards, Series: eco-efficiency in industry and science, vol. 7; 2002.