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