@article{GDZPPN002370441, title = {A convergence criterion for Fourier series}, journal = {Mathematische Zeitschrift}, volume = {28}, year = {1928}, pages = {612-634}, zbl = {54.0301.03}, url = {http://dml.mathdoc.fr/item/GDZPPN002370441} }
Hardy, G. H., und J.; J. E. Littlewood. A convergence criterion for Fourier series. Mathematische Zeitschrift, Tome 28 (1928) pp. 612-634. http://gdmltest.u-ga.fr/item/GDZPPN002370441/