@article{GDZPPN002295482,
title = {A Spectral Theory for Certain Operators on a Direct Sum of Hilbert Spaces.},
journal = {Mathematische Annalen},
volume = {161},
year = {1965},
pages = {294-330},
zbl = {0139.31202},
url = {http://dml.mathdoc.fr/item/GDZPPN002295482}
}
DUNFORD, N. A Spectral Theory for Certain Operators on a Direct Sum of Hilbert Spaces.. Mathematische Annalen, Tome 161 (1965) pp. 294-330. http://gdmltest.u-ga.fr/item/GDZPPN002295482/