  The Sznajd model in less than a year has found several followers. An isolated
person does not convince others; a group of people sharing the same opinions
influences the neighbours much more easily. Thus on a square lattice, with
variables +1 (Democrats) and --1 (Republicans) on every lattice site, a pair
(or plaquette) of neighbours convinces its six (eight) nearest neighbours of
its own opinion if and only if all members of the pair (plaquette) share the
same opinion. The generalization to many possible states is used to explain the
distribution of votes among candidates in Brazilian local elections.
  Review; published in Journal of Artificial Societies and Social Simulation 5,
No. 1, paper 4 (2002), available only electronically
