@article{AIF_1980__30_2_97_0,
     author = {Dahlberg, Bj\"orn E. J.},
     title = {Approximation of harmonic functions},
     journal = {Annales de l'Institut Fourier},
     pages = {97--107},
     publisher = {Institut Fourier},
     address = {Grenoble},
     volume = {30},
     number = {2},
     year = {1980},
     doi = {10.5802/aif.787},
     mrnumber = {82i:31010},
     zbl = {0417.31005},
     language = {en},
     url = {http://www.numdam.org/articles/10.5802/aif.787/}
}