Acoustical techniques and transducers : loudspeakers, microphones, gramophone pick-ups, room acoustics, vibration measurements, stereophonic reproduction / M. L. Gayford. Gayford, M. L. [from old catalog] Electro-acoustics. Transducers. TK5981 .G3 620.102 GAA includes index. London : Macdonald and Evans ; c1961. c1961. 1961 Text xx, 372 P. : eng