@article{MZ_1950__52_169109,
     author = {H. Seifert},
     title = {Schlingknoten},
     journal = {Mathematische Zeitschrift},
     pages = {62--80},
     publisher = {mathdoc},
     volume = {52},
     year = {1950},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MZ_1950__52_169109/}
}