@article{MAN_1966__163_161366,
     author = {H.O. Cordes},
     title = {\"Uber eine nichtalgebraische {Charakterisierung} von {I-Fredholm-Operatoren.}},
     journal = {Mathematische Annalen},
     pages = {212--229},
     publisher = {mathdoc},
     volume = {163},
     year = {1966},
     zbl = {0137.31901},
     url = {http://geodesic.mathdoc.fr/item/MAN_1966__163_161366/}
}