TY - RPRT TI - Blade vortex interaction noise reduction techniques for a rotorcraft AU - Charles, Bruce D. AU - Hassan, Ahmed A. AU - Tadghighi, Hormoz AU - JanakiRam, Ram D. AU - Sankar, Lakshmi N. PY - 1998 UR - https://ntrs.nasa.gov/citations/20080004608 ID - 20080004608 ER -