@article{ HL97,
  author =           {Hiss, G. and Lübeck, F.},
  title =            {The {B}rauer trees of the exceptional groups  of  type
                      {$F_4$} and {$^2E_6$}},
  journal =          {Arch. Math. (Basel)},
  volume =           {70},
  year =             {1998},
  pages =            {16--21}
}