Proof verification and the hardness of approximation problems. Mihir Bellare, Oded Goldreich, and Madhu Sudan. Richard Chang, William I. Gasarch, and Carsten Lund. On bounded queries and approximation. Uriel Feige and Joe Kilian.
Impossibility results for recycling random bits in two-prover proof systems.
A Chernoff bound for random walks on expander graphs. Oded Goldreich and Avi Wigderson. Oded Goldreich and Avi Wigderson. Russell Impagliazzo and Avi Wigderson. David R. Karger and Rajeev Motwani.