@article{GDZPPN002302136, title = {Spectral Analysis Using Ascent, Descent, Nullity and Defect.}, journal = {Mathematische Annalen}, volume = {189}, year = {1970}, pages = {197-214}, zbl = {0177.17102}, url = {http://dml.mathdoc.fr/item/GDZPPN002302136} }
LAY, D.C. Spectral Analysis Using Ascent, Descent, Nullity and Defect.. Mathematische Annalen, Tome 189 (1970) pp. 197-214. http://gdmltest.u-ga.fr/item/GDZPPN002302136/