@article{MABA_1992_6_3_a4,
     author = {Laura Burlando},
     title = {Generalized {Semi-Fredholm} {Operators} {That} {Belong} to the {Closure} of the {Group} of {Invertible} {Operators}},
     journal = {Mathematica balkanica},
     pages = {223},
     publisher = {mathdoc},
     volume = {6},
     number = {3},
     year = {1992},
     url = {http://geodesic.mathdoc.fr/item/MABA_1992_6_3_a4/}
}