@article{GDZPPN002074702,
title = {Ungel\"oste Probleme.},
journal = {Elemente der Mathematik},
volume = {15},
year = {1960},
pages = {130-131},
url = {http://dml.mathdoc.fr/item/GDZPPN002074702}
}
Hadwiger, H. Ungelöste Probleme.. Elemente der Mathematik, Tome 15 (1960) pp. 130-131. http://gdmltest.u-ga.fr/item/GDZPPN002074702/