External finite element approximations of eigenvalue problems M. Vanmaele; A. Ženíšek — 1993 ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique
Finite element solution of nonlinear elliptic equations with discontinuous coefficients and approximations in Sobolev-Slobodeckij spaces Feistauer, M.; Ženíšek, A. — 1990 Equadiff 7