A lower bound for the Graver complexity of the incidence matrix of a   complete bipartite graph
  We give an exponential lower bound for the Graver complexity of the incidence matrix of a complete bipartite graph of arbitrary size. Our result is a generalization of the result by Berstein and Onn (2009) for 3xr complete bipartite graphs, r \ge 3. 
Taisei Kudo and Akimichi Takemura
math.ST stat.TH