@article{RCM_1974__8_181626,
     author = {Jaime Lesmes},
     title = {On the approximation of continuosly diffentialble functions in  {Hilbert} spaces},
     journal = {Revista colombiana de matematicas},
     pages = {217--224},
     publisher = {mathdoc},
     volume = {8},
     year = {1974},
     zbl = {0293.41032},
     url = {http://geodesic.mathdoc.fr/item/RCM_1974__8_181626/}
}