1. The Möbius function and connected graphs;Cadogan;J. Combinatorial Theory II B,1971
2. Polya's theory of counting;DeBruijn,1964
3. Graphical Enumeration;Harary,1973
4. Enumeration of bicolorable graphs;Harary;Canad. J. Math.,1963
5. Contributions to the theory of condensation;Riddell,1951