@article{AM2_1992__44_1_137490,
     author = {Alberto Cavicchioli},
     title = {Neuwirth manifolds and colourings of graphs.},
     journal = {Aequationes mathematicae},
     pages = {168--187},
     year = {1992},
     volume = {44},
     number = {1},
     zbl = {0772.57021},
     url = {http://geodesic.mathdoc.fr/item/AM2_1992__44_1_137490/}
}