"United States. Army Aviation Research and Technology Activity. Aeroflightdynamics Directorate." . . . . . . . . . . . . . . . . . "An experimental investigation of the flap-lag-torsion aeroelastic stability of a small-scale hingeless helicopter rotor in hover"@en . . "An experimental investigation of the flap-lag-torsion aeroelastic stability of a small-scale hingeless helicopter rotor in hover" . . . . . . .