NF S31-004-6*NF EN 12354-6:2004 Building acoustics - Estimation of acoustic performance of buildings from the performance of elements - Part 6 : sound absorption in enclosed spaces
2004NF S31-004-6*NF EN 12354-6:2004 Building acoustics - Estimation of acoustic performance of buildings from the performance of elements - Part 6 : sound absorption in enclosed spaces