@article{MZ_1976__148_172346,
     author = {Hans-Bernd Knoop and Peter Pottinger},
     title = {Ein {Satz} vom {Korovkin-Typ} f\"ur {Ck-R\"aume.}},
     journal = {Mathematische Zeitschrift},
     pages = {23--32},
     publisher = {mathdoc},
     volume = {148},
     year = {1976},
     zbl = {0322.41016},
     url = {http://geodesic.mathdoc.fr/item/MZ_1976__148_172346/}
}