@article{MZ_1919__4_167521,
     author = {G., Szeg\"o},
     title = {\"Uber {Orthogonalsysteme} von {Polynomen}},
     journal = {Mathematische Zeitschrift},
     pages = {139--151},
     publisher = {mathdoc},
     volume = {4},
     year = {1919},
     zbl = {47.0335.01},
     url = {http://geodesic.mathdoc.fr/item/MZ_1919__4_167521/}
}