@article{ELMA_1958__13_140676,
     author = {H. Hadwiger},
     title = {Ungel\"oste {Probleme.}},
     journal = {Elemente der Mathematik},
     pages = {30--31},
     year = {1958},
     volume = {13},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1958__13_140676/}
}