1. Free Field response of Condenser Microphones Brüel & Kjær Technical Review No.1 and 2, 1959
2. AIP Handbook of Condenser Microphones pg 43 and ff Edited by George S. Wong and Tony E. W. Embleton American Institute of Physics, New York
3. Microphone Handbook Vol. 1, Theory, BE1447-11, 1996, Brüel & Kjær Sound & Vibration Measurements A/S
4. Microphone Handbook Vol. 2, Falcon Range Microphones, BE1373-12, 1995, Brüel & Kjær Sound & Vibration Measurements A/S