@article{MZ_1928__27_167993,
     author = {E. Sperner},
     title = {Ein {Satz} \"uber {Untermengen} einer endlichen {Menge}},
     journal = {Mathematische Zeitschrift},
     pages = {544--548},
     publisher = {mathdoc},
     volume = {27},
     year = {1928},
     zbl = {54.0090.06},
     url = {http://geodesic.mathdoc.fr/item/MZ_1928__27_167993/}
}