@Unpublished{Muller10MITRA, author = {E. Staab and G. Muller}, title = {{$\mathcal{M}$ITRA}: A Meta-Model for Information Flow in Trust and Reputation Architectures}, url = {http://arxiv.org/abs/1207.0405}, OPTkey = {}, OPTmonth = {}, OPTyear = {}, OPTannote = {} }