@article{MZ_1928__28_168036,
     author = {A., Wintner},
     title = {Zur {Analysis} im {Hilbertschen} {Raume}},
     journal = {Mathematische Zeitschrift},
     pages = {451--470},
     publisher = {mathdoc},
     volume = {28},
     year = {1928},
     zbl = {54.0424.03},
     url = {http://geodesic.mathdoc.fr/item/MZ_1928__28_168036/}
}