@article{MAN_1988__282_2_164474,
     author = {M. P. Heble},
     title = {Approximation of {Differentiable} {Functions} on a {Hilbert} {Space.} {III.}},
     journal = {Mathematische Annalen},
     pages = {473--484},
     publisher = {mathdoc},
     volume = {282},
     number = {2},
     year = {1988},
     zbl = {0627.46044},
     url = {http://geodesic.mathdoc.fr/item/MAN_1988__282_2_164474/}
}