@article{MZ_1931__33_168278,
     author = {K., Menger},
     title = {Beitr\"age zur {Gruppentheorie.} {I.} {\"Uber} eine {Gruppenmetrik}},
     journal = {Mathematische Zeitschrift},
     pages = {396--418},
     publisher = {mathdoc},
     volume = {33},
     year = {1931},
     zbl = {57.0151.03},
     url = {http://geodesic.mathdoc.fr/item/MZ_1931__33_168278/}
}