1. Sejnowski, T.J. & Rosenberg, C.R. The Johns Hopkins University Electrical Engineering and Computer Science Technical Report JHU/EECS–86/01 (Baltimore, Maryland, 1986).
2. Hopfield, J.J. & Tank, D.W. Biol. Cybernet. 5, 141 (1985).
3. Rumelhart, D.E., Hinton, G.E. & Williams, R.J. in Parallel, Distributed Processing: Explorations in the Microstructure of Cognition (eds Rumelhart, D.E. & McClelland, J.L.) (MIT, Cambridge, in the press).
4. Parker, D. MIT Tech. Rep. TR–47 (1085).
5. Yann Le Cun in Disordered Systems and Biological Organization (eds Bienenstock, E., Fogelman Soulie, F. & Weisbuch, G.) (Springer, Berlin, in the press).