@article{GDZPPN002073846,
title = {Ungel\"oste Probleme.},
journal = {Elemente der Mathematik},
volume = {10},
year = {1955},
pages = {130-132},
url = {http://dml.mathdoc.fr/item/GDZPPN002073846}
}
Hadwiger, H. Ungelöste Probleme.. Elemente der Mathematik, Tome 10 (1955) pp. 130-132. http://gdmltest.u-ga.fr/item/GDZPPN002073846/