1. Directive 2002/49/EC of the European Parliament and of the Council of June 25, 2002 relating to the assessment and management of environmental noise. OJEC 189(12), July 18 (2002)
2. ISO 3095: 2005: Railway Applications - Acoustics - Measurement of noise emitted by railbound vehicle, August 15 (2005)
3. Kuijpers, A.H.W.M.: Rail roughness monitoring in the Netherlands. NNFM, vol. 99, pp. 348–354 (2008)
4. Verheijen, E., van Beek, A.: Definition of track influence: roughness in rolling noise, Harmonoise deliverable D12 part 1, appendix 7, doc. id. HAR12TR-020813-AEA10, July 17 (2003)
5. Kuijpers, A.H.W.M., Schwanen, W., van Dijck, B.H.C.A.: Controlling rail roughness as a noise mitigation measure: from pilot project to implementation (in Dutch), M+P report M+P.RAIL.06.15.11 rev 4, February 2 (2009)