@article{MZ_1955__63_169523,
     author = {Erich H. Rothe},
     title = {Mapping degree in {Banach} spaces and spectral theory.},
     journal = {Mathematische Zeitschrift},
     pages = {195--218},
     publisher = {mathdoc},
     volume = {63},
     year = {1955},
     zbl = {0065.35503},
     url = {http://geodesic.mathdoc.fr/item/MZ_1955__63_169523/}
}