@article{10_4064_sm_114_1_13_27,
     author = {Manuel Gonz\'alez},
     title = {Operational quantities characterizing {semi-Fredholm} operators},
     journal = {Studia Mathematica},
     pages = {13--27},
     publisher = {mathdoc},
     volume = {114},
     number = {1},
     year = {1995},
     doi = {10.4064/sm-114-1-13-27},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-114-1-13-27/}
}