@article{MZ_1986__193_173808,
     author = {C.M. Edwards and G.T. R\"uttimann},
     title = {On the {Facial} {Structure} of the {Unit}  {Ball} of a {GM-Space.}},
     journal = {Mathematische Zeitschrift},
     pages = {597--612},
     publisher = {mathdoc},
     volume = {193},
     year = {1986},
     zbl = {0612.46017},
     url = {http://geodesic.mathdoc.fr/item/MZ_1986__193_173808/}
}