@article{MZ_1950__52_169142,
     author = {SZASZ and O.},
     title = {On a summation method of 0. {Perron}},
     journal = {Mathematische Zeitschrift},
     pages = {631--636},
     year = {1950},
     volume = {52},
     zbl = {0041.18501},
     url = {http://geodesic.mathdoc.fr/item/MZ_1950__52_169142/}
}