@article{GDZPPN001174118,
title = {Approximation in Variationally Posed Eigenvalue Problems.},
journal = {Numerische Mathematik},
volume = {28},
year = {1977},
pages = {159-172},
zbl = {0352.65059},
url = {http://dml.mathdoc.fr/item/GDZPPN001174118}
}
Kolata, W.G. Approximation in Variationally Posed Eigenvalue Problems.. Numerische Mathematik, Tome 28 (1977) pp. 159-172. http://gdmltest.u-ga.fr/item/GDZPPN001174118/