@article{MAN_1925__93_159084,
     author = {H. Looman},
     title = {\"Uber die {Perronsche} {Integraldefinition}},
     journal = {Mathematische Annalen},
     pages = {153--156},
     publisher = {mathdoc},
     volume = {93},
     year = {1925},
     zbl = {50.0180.02},
     url = {http://geodesic.mathdoc.fr/item/MAN_1925__93_159084/}
}