@article{10_4064_ap103_1_2,
     author = {George A. Anastassiou},
     title = {General uniform approximation theory by multivariate
  singular integral operators},
     journal = {Annales Polonici Mathematici},
     pages = {15--25},
     publisher = {mathdoc},
     volume = {103},
     number = {1},
     year = {2012},
     doi = {10.4064/ap103-1-2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap103-1-2/}
}