@misc{ELMA_1949__4_140499,
     title = {Aufgaben.},
     journal = {Elemente der Mathematik},
     pages = {15--19},
     publisher = {mathdoc},
     volume = {4},
     year = {1949},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1949__4_140499/}
}