@article{MZ_1958__69_169753,
     author = {M.S. Ramanujan},
     title = {On {Products} of {Summability} {Methods.}},
     journal = {Mathematische Zeitschrift},
     pages = {423--428},
     publisher = {mathdoc},
     volume = {69},
     year = {1958},
     zbl = {0083.04602},
     url = {http://geodesic.mathdoc.fr/item/MZ_1958__69_169753/}
}