@article{MAN_1915__76_158708,
     author = {G. Doetsch and F. Bernstein},
     title = {Zur {Theorie} der konvexen {Funktionen}},
     journal = {Mathematische Annalen},
     pages = {514--526},
     year = {1915},
     volume = {76},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MAN_1915__76_158708/}
}