@article{MZ_1977__155_172549,
     author = {Dietmar Vogt},
     title = {Charakterisierung der {Unterr\"aume} von s.},
     journal = {Mathematische Zeitschrift},
     pages = {109--118},
     publisher = {mathdoc},
     volume = {155},
     year = {1977},
     zbl = {0337.46015},
     url = {http://geodesic.mathdoc.fr/item/MZ_1977__155_172549/}
}