1. Parsing Flowcharts and Series Parallal Graphs;Ayesta,1978
2. On the computer calculation of the number of nonseparable graphs;Butler,1977
3. A Combinatorial Decomposition Theory;Cunningham,1973
4. A combinatorial decomposition theory;Cunningham;Canad. J. Math.,1980
5. Constructive enumeration of combinatorial objects;Faradzhev,1978