1. T. Kailath, Linear Systems, Prentice-Hall, 1980.
2. T. Kailath IEEE Trans. Inform. Thy., pp. 385-386, May 1981
3. T. Kailath IEEE Trans. Autom. Contr., pp. 804-805, June 1981
4. T. Kailath IEEE Circuits and Systems Magazine, p. 21, 1981
5. T. Kailath Proceedings IEEE, pp. 1519-1520, 1981, p. 107 Jan. 1982