Götz Alefeld, Vladik Kreinovich, Günter Mayer. Modifications of the Oettli-Prager Theorem with Application to the Eigenvalue Problem. In Götz Alefeld, Jiri Rohn, Siegfried M. Rump, Tetsuro Yamamoto, editors, Symbolic Algebraic Methods and Verification Methods. pages 11-20, Springer, 2001.
Abstract is missing.