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