1. Directive 89/106/EEC of 21 December 1988 on the approximation of laws, regulations and administrative provisions of the Member States relating to construction products; 1989.
2. COM 311 final. Proposal for a regulation of the European Parliament and of the Council laying down harmonised conditions for the marketing of the construction products; 2008.
3. EN 14411. Ceramic tiles. Definitions, classification, characteristics and marking; 2003.
4. ISO 14040. Environmental management. Life cycle assessment. Requirements and guidelines; 2006.
5. ISO 14044. Environmental management. Life cycle assessment. Principles and framework; 2006.