@article{GDZPPN002299542, title = {Homotopy Properties of Semi-Fredholm Operators in Banach Spaces.}, journal = {Mathematische Annalen}, volume = {179}, year = {1968}, pages = {273-301}, zbl = {0163.37602}, url = {http://dml.mathdoc.fr/item/GDZPPN002299542} }
NEUBAUER, G. Homotopy Properties of Semi-Fredholm Operators in Banach Spaces.. Mathematische Annalen, Tome 179 (1968) pp. 273-301. http://gdmltest.u-ga.fr/item/GDZPPN002299542/