@article{MAN_1904__58_158121,
     author = {A. Sch\"onflies},
     title = {Beitr\"age zur {Theorie} der {Punktmengen.} {I.}},
     journal = {Mathematische Annalen},
     pages = {195--234},
     publisher = {mathdoc},
     volume = {58},
     year = {1904},
     zbl = {34.0074.03},
     url = {http://geodesic.mathdoc.fr/item/MAN_1904__58_158121/}
}