@article{MZ_1963__81_170161,
     author = {Gerald Hammer},
     title = {Ein {Verfahren} zur {Bestimmung} von {Begleitknoten.}},
     journal = {Mathematische Zeitschrift},
     pages = {395--413},
     year = {1963},
     volume = {81},
     zbl = {0136.21202},
     url = {http://geodesic.mathdoc.fr/item/MZ_1963__81_170161/}
}