@article{MOMA_1971__75_177558,
     author = {Susanne Beer and Eugene Lukacs},
     title = {Einf\"uhrung des {Wahrscheinlichkeitsoperators} durch {Postulate.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {291--295},
     publisher = {mathdoc},
     volume = {75},
     year = {1971},
     zbl = {0229.60002},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1971__75_177558/}
}