1. Graphs and Network;Carre,1979
2. N. Chiba, T. Nishizeki, and N. Saito, An approximation algorithm for the maximum independent set problem on planar graphs, submitted for publication.
3. Some simplified NP-complete graph problems;Garey;Theor. Comput. Sci.,1976
4. A batching method for coloring planar graphs;Lipton;Inform. Process. Lett.,1978