@article{MZ_1996__221_1_174860,
     author = {Hubert Berens and Yuan Xu},
     title = {Fej\'er means for multivariate {Fourier} series.},
     journal = {Mathematische Zeitschrift},
     pages = {449--466},
     publisher = {mathdoc},
     volume = {221},
     number = {1},
     year = {1996},
     zbl = {0904.42009},
     url = {http://geodesic.mathdoc.fr/item/MZ_1996__221_1_174860/}
}