1. Commission Directive 2001/116/EC of 20 December 2001. 91/441/EEC Council Directive 91/441/EEC of 26 June 1991 amending Directive 70/220/EEC on the approximation of the laws of the Member States relating to measures to be taken against air pollution by emissions from motor vehicles, Eur-lex.europa.eu., 2011.
2. Commission Directive 2001/116/EC of 20 December 2001. Directive 2002/51/EC of the European Parliament and of the Council of 19 July 2002 on the reduction of the level of pollutant emissions from two- and three-wheel motor vehicles and amending Directive 97/24/EC, Eur-lex.europa.eu., 2011.
3. Commission Directive 2001/116/EC of 20 December 2001. Directive 98/69/EC of the European Parliament and of the Council of 13 October 1998 relating to measures to be taken against air pollution by emissions from motor vehicles and amending Council Directive 70/220/EEC, Eur-lex.europa.eu., 2011.
4. Commission Directive 2001/116/EC of 20 December 2001. Regulation (EC) No 715/2007 of the European Parliament and of the Council of 20 June 2007 on type approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle repair and maintenance information, Eur-lex.europa.eu., 2011.
5. Commission Regulation (EU) No 459/2012 of 29 May 2012. Amending Regulation (EC) No 715/2007 of the European Parliament and of the Council and Commission Regulation (EC) No 692/2008 as regards emissions from light passenger and commercial vehicles (Euro 6), Eur-lex.europa.eu., 2012.