@article{GDZPPN001182773, title = {An a posteriori Error Estimation of the Rayleigh-Ritz Eigenvalues.}, journal = {Numerische Mathematik}, volume = {56}, year = {1989}, pages = {639-654}, zbl = {0645.65027}, url = {http://dml.mathdoc.fr/item/GDZPPN001182773} }
Zitnan, Peter. An a posteriori Error Estimation of the Rayleigh-Ritz Eigenvalues.. Numerische Mathematik, Tome 56 (1989) pp. 639-654. http://gdmltest.u-ga.fr/item/GDZPPN001182773/