Measurement and characterisation of ultrasonic fields using hydrophones in the frequency range 0,5 MHz to 15 MHz (IEC 61102:1991 + A1:1993); German version EN 61102:1993 + A1:1994— 31 стр.
Requirements for the declaration of the acoustic output of medical diagnostic ultrasonic equipment (IEC 61157:1992); German version EN 61157:1994— 18 стр.