@misc{MZ_1924__19_167766,
     title = {Hardy, {G.} {H.,} and {J.} {E.} {Littlewood,} {Solution} of the                   {Ces\`aro} summability problem for power-series and {Fourier} series},
     journal = {Mathematische Zeitschrift},
     pages = {67--96},
     publisher = {mathdoc},
     volume = {19},
     year = {1924},
     zbl = {49.0232.01},
     url = {http://geodesic.mathdoc.fr/item/MZ_1924__19_167766/}
}