Uriel Feige, Michael Langberg, Kobbi Nissim. On the hardness of approximating ::::N P:::: witnesses. In Klaus Jansen, Samir Khuller, editors, Approximation Algorithms for Combinatorial Optimization, Third International Workshop, APPROX 2000, Saarbrücken, Germany, September 5-8, 2000, Proceedings. Volume 1913 of Lecture Notes in Computer Science, pages 120-131, Springer, 2000. [doi]
Abstract is missing.