@article{JRAM_1973__259_151305,
     author = {Syed A. Husain},
     title = {Convergence factors of {Fourier} series of summable functions.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {183--185},
     publisher = {mathdoc},
     volume = {259},
     year = {1973},
     zbl = {0264.42007},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1973__259_151305/}
}