@misc{ELMA_1967__22_140869,
     title = {Aufgaben.},
     journal = {Elemente der Mathematik},
     pages = {136--139},
     publisher = {mathdoc},
     volume = {22},
     year = {1967},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1967__22_140869/}
}