1. Proof verification and hardness of approximation problems;Arora,1992
2. The complexity of manipulating hierarchically defined set of rectangles;Bentley,1984
3. Unit disk graphs;Clark;Discrete Math.,1990
4. Strongly polynomial-time and NC algorithms for detecting cycles in dynamic graphs;Cohen,1989
5. Probabilistically checkable debate systems and approximation algorithms for PSPACE-Hard Functions;Condon,1993