KayL., “Air Sonars with Acoustical Display of Spatial Information” in Animal Sonar Systems (ed. BusnelR. G.) (Pergamon PressNew York, 1979).
3.
KayL.“A Sonar Aid to Enhance Spatial Perception of the Blind: Engineering Design and evaluation”, The Radio and Electronic Engineer, 44, p. 605–627, 1974.
