1. Potter, R.K., Kopp, G.A., and Green, H.C.: Visible Speech, (Van Nostrand, New York 1947)
2. Flanagan, J.L.: Speech Analysis, Synthesis and Perception, (Springer-Verlag, New York 1965)
3. Woodward, P.M.: Probability and Information Theory, with Applications to Radar, 2nd edn.(Pergamon, London 1964)
4. Benjamin, R.: Modulation, Resolution and Signal Processing in Radar, Sonar and Related Systems, (Pergamon, London 1966)