1. RRAE – Portuguese regulation on acoustic requirements for buildings, approved by Decree Law n° 129/2002 of 11/05 with new wording given in Decree Law n° 96/2008 of 09/06
2. ANSI S12.60-2002 (2002) Acoustical performance criteria, design requirements and guidelines for schools. American National Standards Institute, Washington, DC
3. RGR – General Portuguese regulation on noise, approved by Decree Law n° 9/2007 de 17/01