@article{MAN_1976__223_162886, author = {Richard C. O'Brien}, title = {On the {Openness} of the {Barycentre} {Map.}}, journal = {Mathematische Annalen}, pages = {207--212}, publisher = {mathdoc}, volume = {223}, year = {1976}, zbl = {0321.46004}, url = {http://geodesic.mathdoc.fr/item/MAN_1976__223_162886/} }