1. Alexander, W. N., Devenport, W. J., Clark I. A., Jaworski, J. W., Glegg, S., Peake, N. and Daly, C., 2014, "Noise Reduction Surface Treatment for Airfoil", International Patent Application PCT/US14/59508.
2. Choi, K., and Simpson, R.L., 1987, "Some Mean Velocity, Turbulence and Unsteadiness Characteristics of the VPI & SU Stability Wind Tunnel," Department of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, Report VPI-Aero-161.
3. The Kevlar-walled anechoic wind tunnel
4. The far-field sound from rough-wall boundary layers