@article{1183504979,
author = {Oberg, Edwin N.},
title = {On the approximation of functions by sums of orthonormal functions},
journal = {Bull. Amer. Math. Soc.},
volume = {49},
number = {12},
year = {1943},
pages = { 68-80},
language = {en},
url = {http://dml.mathdoc.fr/item/1183504979}
}
Oberg, Edwin N. On the approximation of functions by sums of orthonormal functions. Bull. Amer. Math. Soc., Tome 49 (1943) no. 12, pp. 68-80. http://gdmltest.u-ga.fr/item/1183504979/