1. General theory of aerodynamic instability and the mechanism of flutter;Theodorsen;NACA Report 496,1935
2. Airfoil in sinusoidal motion in pulsating stream;Greenberg;NACA TN 1329,1947
3. Two-dimensional approximation to the unsteady aerodynamics of rotary wings;Loewy;Journal of the Aeronautical Sciences,1957
4. Two-dimensional approximation to the unsteady aerodynamics of rotary wings;Loewy;Journal of the Aeronautical Sciences,1957
5. A two-dimensional theory for rotor blade flutter in forward flight;Shipman;Journal of Aircraft,1971