@article{ HL95,
  author =           {Hiss, G. and Lübeck, F. and Malle, G.},
  title =            {The {B}rauer  trees  of  the  exceptional  {C}hevalley
                      groups of type {$E_6$}},
  journal =          {Manuscripta Math.},
  volume =           {87},
  year =             {1995},
  pages =            {131--144}
}