1. J. von Neumann: The Computer and the Brain ( Yale University Press, New Haven 1958 )
2. F. Attneave: Psychol. Rev. 61, 183–193 (1954)
3. H.B. Barlow: In Sensory Communication, ed. W.A. Rosenblith ( MIT Press, Cambridge, Mass. 1961 ) pp. 217–234
4. H.B. Barlow: In Sensory Communication, ed. W.A. Rosenblith ( MIT Press, Cambridge, Mass. 1961 ) pp. 782–786
5. H.B. Barlow: In Current Problems in Animal Behaviour, eds. W.H. Thorpe, O.L. Zangwill ( Cambridge University Press, Cambridge 1961 ) pp. 331–360