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@article{PIM_1997_N_S_61_75_a9, author = {Sne\v{z}ana \v{Z}ivkovi\'c}, title = {Semi-Fredholm {Operators} and {Perturbations}}, journal = {Publications de l'Institut Math\'ematique}, pages = {73 }, publisher = {mathdoc}, volume = {_N_S_61}, number = {75}, year = {1997}, zbl = {0889.47003}, language = {en}, url = {http://geodesic.mathdoc.fr/item/PIM_1997_N_S_61_75_a9/} }
Snežana Živković. Semi-Fredholm Operators and Perturbations. Publications de l'Institut Mathématique, _N_S_61 (1997) no. 75, p. 73 . http://geodesic.mathdoc.fr/item/PIM_1997_N_S_61_75_a9/