@article{GDZPPN002408376,
title = {Generalisation of Rellich's Theorem on Perturbation of (Essentially) Selfadjoin Operators.},
journal = {Mathematische Zeitschrift},
volume = {121},
year = {1971},
pages = {276-280},
zbl = {0228.47010},
url = {http://dml.mathdoc.fr/item/GDZPPN002408376}
}
Wüst, Rainer. Generalisation of Rellich's Theorem on Perturbation of (Essentially) Selfadjoin Operators.. Mathematische Zeitschrift, Tome 121 (1971) pp. 276-280. http://gdmltest.u-ga.fr/item/GDZPPN002408376/