Glenn S. Fowler Robert M. Haralick F. Gail Gray Charles Feustel Charles Grinstead Efficient Graph Automorphism by Vertex Partitioning. 245-269 1983 21 Artif. Intell. 1-2 db/journals/ai/ai21.html#FowlerHGFG83 http://dx.doi.org/10.1016/S0004-3702(83)80012-5