@article{PM_1990_1990_1_a23,
     author = {Bercovici, Hari},
     title = {Operadores {C0-Fredholm} {(IV).}},
     journal = {Publicacions matem\`atiques},
     pages = {277-290},
     year = {1990},
     volume = {34},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PM_1990_1990_1_a23/}
}