Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{ELMA_1963__18_140781, author = {H. Lenz}, title = {Ungel\"oste {Probleme.}}, journal = {Elemente der Mathematik}, pages = {134--134}, publisher = {mathdoc}, volume = {18}, year = {1963}, url = {http://geodesic.mathdoc.fr/item/ELMA_1963__18_140781/} }
H. Lenz. Ungelöste Probleme.. Elemente der Mathematik, Tome 18 (1963), p. 134. http://geodesic.mathdoc.fr/item/ELMA_1963__18_140781/