@article{MAN_1978__236_163172,
     author = {Klaus Donner and Heinz Bauer},
     title = {Korovkin {Approximation} in {C0(X).}},
     journal = {Mathematische Annalen},
     pages = {225--238},
     year = {1978},
     volume = {236},
     zbl = {0368.46028},
     url = {http://geodesic.mathdoc.fr/item/MAN_1978__236_163172/}
}