@article{ELMA_1958__13_140686,
     author = {F. Leuenberger},
     title = {Einige {Dreiecksungleichungen.}},
     journal = {Elemente der Mathematik},
     pages = {121--126},
     year = {1958},
     volume = {13},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1958__13_140686/}
}