1. R.C. Read and D.G. Corneil, The graph isomorphism disease, J. Graph Theory, 1 (1977), 339–363.
2. A. Mowshowitz, The adjacency matrix and the group of a graph, in New Directions in the Theory of Graphs, edited by F. Harary, Academic Press, 1973.
3. Lecture Notes in Mathematics;R.A. Bari,1974
4. J. Turner, Generalized matrix functions and the graph isomorphism problem, Siam J. App. Math., 16 (1968), 520–526.
5. J.F. Meyer, Algebraic isomorphism invariants for graphs of automata, in Graph Theory and Computing, edited by R.C. Read, Academic Press, N.Y., 1972.