%0 Journal Article %A Moran, Siegfried %T Pre-Tits Systems %J Canadian mathematical bulletin %D 1986 %P 486-494 %V 29 %N 4 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1986-077-4/ %R 10.4153/CMB-1986-077-4 %F 10_4153_CMB_1986_077_4