@article{MZ_1971__123_171629,
     author = {Egon Scheffold},
     title = {Das {Spektrum} von {Verbandsoperatoren} in {Banachverb\"anden.}},
     journal = {Mathematische Zeitschrift},
     pages = {177--190},
     publisher = {mathdoc},
     volume = {123},
     year = {1971},
     zbl = {0211.44703},
     url = {http://geodesic.mathdoc.fr/item/MZ_1971__123_171629/}
}