@article{00039577,
title = {Approximation by double Walsh polynomials.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {15},
year = {1992},
pages = {209-220},
doi = {10.1155/S0161171292000279},
zbl = {0817.42014},
language = {en},
url = {http://dml.mathdoc.fr/item/00039577}
}
Móricz, Ferenc. Approximation by double Walsh polynomials.. International Journal of Mathematics and Mathematical Sciences, Tome 15 (1992) pp. 209-220. doi : 10.1155/S0161171292000279. http://gdmltest.u-ga.fr/item/00039577/