1. Bargmann, V., D. Montgomery andJ. von Neumann: Solution of linear systems of high order. Report prepared under contract NORD 9596 with the Bureau of Ordnance, Navy Department, Institute for Advanced Study, 1946.
2. Bauer, F. L.: On the definition of condition numbers and their relation to closed methods for solving linear systems. Proceedings of the International Conference on Information Processing, Unesco, Paris 1960, pp. 109?110.
3. ?, andA. S. Householder: Moments and characteristic roots. Numerische Math.2, 42?53 (1960).
4. ?, andC. T. Fike: Norms and exclusion theorems. Numerische Math.2, 137?141 (1960).
5. Farnell, A. B.: Limits for the field of values of a matrix. Amer. Math. Monthly52, 488?493 (1945).