@article{1077477034,
author = {Rudin, Walter},
title = {$L^2$ -approximation by partial sums of orthogonal developments},
journal = {Duke Math. J.},
volume = {19},
number = {1},
year = {1952},
pages = { 1-4},
language = {en},
url = {http://dml.mathdoc.fr/item/1077477034}
}
Rudin, Walter. $L^2$ -approximation by partial sums of orthogonal developments. Duke Math. J., Tome 19 (1952) no. 1, pp. 1-4. http://gdmltest.u-ga.fr/item/1077477034/