@article{GDZPPN002074494, title = {Ungel\"oste Probleme.}, journal = {Elemente der Mathematik}, volume = {14}, year = {1959}, pages = {82-83}, url = {http://dml.mathdoc.fr/item/GDZPPN002074494} }
Hadwiger, H. Ungelöste Probleme.. Elemente der Mathematik, Tome 14 (1959) pp. 82-83. http://gdmltest.u-ga.fr/item/GDZPPN002074494/