@article{MZ_1962__78_170028,
     author = {G\'eza Freud},
     title = {\"Uber trigonometrische {Approximation} und {Fouriersche} {Reihen.}},
     journal = {Mathematische Zeitschrift},
     pages = {252--262},
     publisher = {mathdoc},
     volume = {78},
     year = {1962},
     zbl = {0101.04802},
     url = {http://geodesic.mathdoc.fr/item/MZ_1962__78_170028/}
}