@article{MAN_1915__76_158704,
     author = {O. Perron},
     title = {Ein neuer {Existenzbeweis} f\"ur die {Integrale} der {Differentialgleichung} y = f (x,y). {(Mit} 2 {Figuren} im {Text).}},
     journal = {Mathematische Annalen},
     pages = {471--484},
     publisher = {mathdoc},
     volume = {76},
     year = {1915},
     zbl = {45.0469.01},
     url = {http://geodesic.mathdoc.fr/item/MAN_1915__76_158704/}
}