@article{GDZPPN002074885, title = {Ungel\"oste Probleme.}, journal = {Elemente der Mathematik}, volume = {17}, year = {1962}, pages = {14-15}, url = {http://dml.mathdoc.fr/item/GDZPPN002074885} }
Hadwiger, H. Ungelöste Probleme.. Elemente der Mathematik, Tome 17 (1962) pp. 14-15. http://gdmltest.u-ga.fr/item/GDZPPN002074885/