@article{MAN_1917__78_158754,
     author = {A. Haar},
     title = {Reihenentwicklungen nach {Legendreschen} {Polynomen}},
     journal = {Mathematische Annalen},
     pages = {121--136},
     publisher = {mathdoc},
     volume = {78},
     year = {1917},
     zbl = {46.0571.01},
     url = {http://geodesic.mathdoc.fr/item/MAN_1917__78_158754/}
}