@article{MET_1972__19_175523,
     author = {W. Widdra},
     title = {Eine {Verallgemeinerung} des {\^A?Gesetzes} seltener {Ereignisse}},
     journal = {Metrika},
     pages = {68--71},
     publisher = {mathdoc},
     volume = {19},
     year = {1972},
     zbl = {0246.60026},
     url = {http://geodesic.mathdoc.fr/item/MET_1972__19_175523/}
}