1. Graphs and Hypergraphs;Berge,1973
2. Representation; noyaux en theorie des graphes et hypergraphes;Duchet,1979
3. Graphes Noyau-parfaits;Duchet;Ann. Discrete Math.,1980
4. A note on kernel-critical graphs;Duchet;Discrete Math.,1981
5. Problems and results in Number Theory and Graph Theory;Erdös,1979