@article{ELMA_1969__24_140913,
     author = {H. Guggenheimer},
     title = {Bemerkung zur {Aufgabe} 493.},
     journal = {Elemente der Mathematik},
     pages = {17--17},
     publisher = {mathdoc},
     volume = {24},
     year = {1969},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1969__24_140913/}
}