@article{MZ_1955__63_169513,
     author = {Konrad Knopp},
     title = {N\"orlund-Verfahren f\"ur {Funktionen.} {(Zweite} {Mitteilung).}},
     journal = {Mathematische Zeitschrift},
     pages = {39--52},
     publisher = {mathdoc},
     volume = {63},
     year = {1955},
     zbl = {0067.28801},
     url = {http://geodesic.mathdoc.fr/item/MZ_1955__63_169513/}
}