@article{1077491919, author = {Offord, A. C.}, title = {Approximation to functions by trigonometric polynomials}, journal = {Duke Math. J.}, volume = {6}, number = {1}, year = {1940}, pages = { 505-510}, language = {en}, url = {http://dml.mathdoc.fr/item/1077491919} }
Offord, A. C. Approximation to functions by trigonometric polynomials. Duke Math. J., Tome 6 (1940) no. 1, pp. 505-510. http://gdmltest.u-ga.fr/item/1077491919/