1. a) R.B. King, ed. Chemical Applications of Topology and Graph Theory; Studies in Physical and Theoretical Chemistry Vol. 28 (Elsevier, Amsterdam, 1983); references are from the Russian translation (Mir Publ., Moscow., 1987); b) R.F.W. Bader, p. 54 in ref. la; c) P.Mezey, p. 91 in ref. la; d) M.J. McGlinchey, Y. Tal, p. 148 inref. la.
2. A. T. Balaban, ed. Chemical Applications of Graph Theory (Academic Press, Lon-don, 1976).
3. Book Review: P. Mezey, J. Comput. Chem., 12(1991)139 about R. E. Merrifield, H. E. Simmons Topological Methods in Chemistry (Wiley Interscience, New York, 1989).
4. H. Seifert, W. Trelfall A Textbook of Topology Pure and Appl. Math. Ser., 1980.
5. P. J. Giblin Graphs
Surfaces and Homology: An Introduction to Algebraic Topo-logy 2nd edn., (Chapman and Hall, New York, London, 1981).