@article{MAN_1937__114_159931,
     author = {O. Perron},
     title = {Bemerkung zu einem {Irreduzibilit\"atskriterium} des {Herrn} {Petterson}},
     journal = {Mathematische Annalen},
     pages = {526--529},
     year = {1937},
     volume = {114},
     zbl = {63.0044.01},
     url = {http://geodesic.mathdoc.fr/item/MAN_1937__114_159931/}
}