[Reports] / Amer.inst.of aeronautics and astronautics. N 90-3987 : Acoustic spectra and detection of vibrating rotor blades,including rowto-row interference : Rep.presented at the AIAA 13th aeroacoustics conf.,Oct.22-24,1990,Tallahassee(Fl) / V.G.Mengle, 1990. - 12 p. - Текст : непосредственный.