Reduction theory for average-case complexity. Proceedings of the 4th Workshop on Computer Science Logic, vol 533 of Lecture Notes in Computer Science, Springer, pages 17-30, 1991. A. Blass and Y. Gurevich. Randomizing reductions of search problems. A. Blass and Y. Gurevich.
Matrix transformation is complete for the average case.
A Random NP-complete problem for inversion of 2D Cellular Automata. A Random NP-complete problem for inversion of 2D Cellular Automata. B. Durand, and A.-C. Fabret. On the complexity of deadlock detection in families of planar nets. Theoretical Computer Science , to appear.