1. B. Widrow and M. E. Hoff, Jr. Adaptive switching circuits. IRE WESCON Conv. Rec., pages 96–104, 1960. Pt. 4.
2. S. Haykin. Adaptive Filter Theory. Prentice Hall, Englewood Cliffs, NJ, second edition, 1991.
3. P. E. Werbos. Beyond Regression: New Tools for Prediction and Analysis in the Behavioral Sciences. PhD dissertation, Harvard University, Cambridge, MA, Aug. 1974.
4. A. Parker. Learning-Logic, Invention Report S81-64, File 1, Office of Technology Licensing, Stanford University, Stanford, CA, Oct. 1982.
5. D. E. Rumelhart, J. L. McClelland and the PDP Research Group. Parallel distributed processing: explorations in the micro structure of cognition Cambridge, Mass.: MIT Press, 1986.