@misc{ELMA_1948__3_140478,
     title = {Pr\"ufungs- und {\"Ubungsaufgaben.}},
     journal = {Elemente der Mathematik},
     pages = {42--46},
     publisher = {mathdoc},
     volume = {3},
     year = {1948},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1948__3_140478/}
}