@article{MAN_1920__81_158823,
     author = {J. Nielsen},
     title = {\"Uber fixpunktfreie topologische {Abbildungen} geschlossener {Fl\"achen}},
     journal = {Mathematische Annalen},
     pages = {94--96},
     publisher = {mathdoc},
     volume = {81},
     year = {1920},
     zbl = {47.0527.02},
     url = {http://geodesic.mathdoc.fr/item/MAN_1920__81_158823/}
}