Distinguishing colorings of Cartesian products of complete graphs
  We determine the values of s and t for which there is a coloring of the edges of the complete bipartite graph K_{s,t} which admits only the identity automorphism. In particular this allows us to determine the distinguishing number of the Cartesian product of complete graphs. 
Michael J. Fisher (CSU Fresno), Garth Isaak (Lehigh University)