@article{MAN_1891__38_157535,
     author = {Robert Fricke},
     title = {Ueber eine besondere {Classe} discontinuirlicher {Gruppen} reeller linearer {Substitutionen.} {(Mit} einer {Figurentafel.)}},
     journal = {Mathematische Annalen},
     pages = {50--81},
     publisher = {mathdoc},
     volume = {38},
     year = {1891},
     zbl = {23.0138.04},
     url = {http://geodesic.mathdoc.fr/item/MAN_1891__38_157535/}
}