@article{MZ_1963__82_170173,
     author = {Helmut H. Schaefer},
     title = {Eine {Bemerkung} zur {Existenz} invarianter {Teilr\"aume} linearer {Abbildungen.}},
     journal = {Mathematische Zeitschrift},
     pages = {90--90},
     publisher = {mathdoc},
     volume = {82},
     year = {1963},
     zbl = {0123.31301},
     url = {http://geodesic.mathdoc.fr/item/MZ_1963__82_170173/}
}