@article{M2AN_1975__9_2_77_0,
     author = {Cl\'ement, Ph.},
     title = {Approximation by finite element functions using local regularization},
     journal = {ESAIM: Mathematical Modelling and Numerical Analysis },
     pages = {77--84},
     publisher = {Dunod},
     address = {Paris},
     volume = {9},
     number = {R2},
     year = {1975},
     mrnumber = {400739},
     zbl = {0368.65008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/M2AN_1975__9_2_77_0/}
}