1. Linear time simulation of deterministic two-way pushdown automata;Cook,1972
2. An efficient algorithm for graph isomorphism;Corneil;J. ACM,1970
3. An n log n algorithm for minimizing states in a finite automation;Hopcroft,1972
4. An n log n Algorithm for Isomorphism of Planar Triply Connected Graphs;Hopcroft,1971
5. Efficient Planarity Testing;Hopcroft,1972