DIN 45635-11:1987 Measurement of noise emitted by machines; airborne noise emission, enveloping surface method; internal combustion engines
DIN 45635-1:1984 Measurement of noise emitted by machines; airborne noise emission; enveloping surface method; basic method, divided into 3 grades of accuracy
DIN 45635-8:1985 Determination of airborne noise emitted by machines by, measurement of structure borne noise; basic requirements