@article{GDZPPN002373335, title = {An additional note on Parseval's Theorem}, journal = {Mathematische Zeitschrift}, volume = {34}, year = {1932}, pages = {634-636}, zbl = {0003.20303}, url = {http://dml.mathdoc.fr/item/GDZPPN002373335} }
Littlewood, J. E., and G. H. Hardy,. An additional note on Parseval's Theorem. Mathematische Zeitschrift, Tome 34 (1932) pp. 634-636. http://gdmltest.u-ga.fr/item/GDZPPN002373335/