Eric Allender, Klaus-Jörn Lange. Symmetry Coincides with Nondeterminism for Time-Bounded Auxiliary Pushdown Automata. In Proceedings of the 25th Annual IEEE Conference on Computational Complexity, CCC2010, Cambridge, Massachusetts, June 9-12, 2010. pages 172-180, IEEE Computer Society, 2010. [doi]
Abstract is missing.