@article{MAN_1956__131_160499,
     author = {M. Landsberg},
     title = {Der {Durchschnittsgrad} hypercharakteristischer {Filter.}},
     journal = {Mathematische Annalen},
     pages = {429--434},
     publisher = {mathdoc},
     volume = {131},
     year = {1956},
     zbl = {0074.17702},
     url = {http://geodesic.mathdoc.fr/item/MAN_1956__131_160499/}
}