1. J. M. Tyler and T.G. Sofrin Society of Automotive Engineers Transactions 70, 309–332. Axial flow compressor noise studies.
2. Pratt and Whitney Aircraft experience in compressor noise reduction;Sofrin,1966
3. Propagation of sound waves through a blade row
4. Exact solution for radiation of sound from semi-infinite circular duct with application to fans and compressors;Lansing,1967