1. Some aspects of engine noise;Lloyd;Journal of the Royal Aeronautical Society,1959
2. The emission of sound by airscrews;Lynam;Advisory Committee for Aeronautics (London), R. & M. No. 624,1919
3. The acoustics of moving sources with application to airscrews;Bryan;Aeronautical Research Committee (London), R. & M. No. 684,1920
4. Translated as 1948 NACA TM 1195: On the sound field of a rotating airscrew;Gutin;Zhurnal tekhnicheskoi fiziki,1936
5. Noise from propellers with symmetrical sections at zero blade angle;Deming;NACA TN 605,1937