@misc{ELMA_1972__27_141061,
     title = {Aufgaben.},
     journal = {Elemente der Mathematik},
     pages = {64--67},
     publisher = {mathdoc},
     volume = {27},
     year = {1972},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1972__27_141061/}
}