@article{ELMA_1948__3_140483,
     author = {H. Kreis},
     title = {\"Uber die {Grundfunktionen} positiver {Zahlen.}},
     journal = {Elemente der Mathematik},
     pages = {59--61},
     publisher = {mathdoc},
     volume = {3},
     year = {1948},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1948__3_140483/}
}