1. A. T. Balaban, Chemical Applications of Graph Theory, Academic Press, London, 1976.
2. A. R. Leach, Molecular Modelling: Principles and Applications, Longman, Harlow, 1996.
3. P. J. Giblin, Graphs, Surfaces and Homology, Chapman and Hall, London, 1977.
4. F. A. Cotton, Chemical Applications of Group Theory, 3rd ed., Wiley, New York, 1990.
5. P. J. Federico, Descartes on Polyhedra, Springer, New York, 1982. A collection of proofs of the Euler theorem is assembled on web page http://www.ics.uci.edu/~eppstein/junkyard/euler