@article{MAN_1915__76_158682,
     author = {O. Haupt},
     title = {\"Uber eine {Methode} zum {Beweise} von {Oszillationstheoremen}},
     journal = {Mathematische Annalen},
     pages = {67--104},
     publisher = {mathdoc},
     volume = {76},
     year = {1915},
     zbl = {45.0494.01},
     url = {http://geodesic.mathdoc.fr/item/MAN_1915__76_158682/}
}