@article{GDZPPN001164627, title = {Optimale Eigenwerteinschlie\ss ungen.}, journal = {Numerische Mathematik}, volume = {5}, year = {1963}, pages = {246-272}, url = {http://dml.mathdoc.fr/item/GDZPPN001164627} }
LEHMANN, N.J. Optimale Eigenwerteinschließungen.. Numerische Mathematik, Tome 5 (1963) pp. 246-272. http://gdmltest.u-ga.fr/item/GDZPPN001164627/