The calculation of sound-absorption in ventilation and air-conditioning plant /
Brockmeyer, H.
Barrett, D. P.
London :  Property Services Agency Library, 
1974.
Originally published as Berechnung der Geräuschdämpfung in Lüftungs und Klimaanlagen in Heizung Lüftung Klimatechnik Haustechnik, 1972 23 (7) (July), 216-220.