1. European Commission. Directive 70/157/EEC of 6 February 1970 on the approximation of the laws of the Member States relating to the permissible sound level and the exhaust system of motor vehicles.
2. Vehicle refinement: controlling noise and vibration in road vehicles;Harrison,2004
3. Michel U, Barsikow B. Localisation of sound sources on moving vehicles with microphone arrays. Paper ID 537. In: Proc EuroNoise 2003, Neapel, paper ID 537, 19.-21.05.2003; 2003.
4. Sandberg U, Ejsmont JA. Tyre/road noise reference book, vol. 59040. Sweden: Informex Kisa; 2002.
5. ISO 13325. Tyres – coast-by methods for measurement of tyre-to-road sound emission; 2003.