Stanislav Böhm, Stefan Göller, Petr Jancar. Equivalence of deterministic one-counter automata is NL-complete. In Dan Boneh, Tim Roughgarden, Joan Feigenbaum, editors, Symposium on Theory of Computing Conference, STOC'13, Palo Alto, CA, USA, June 1-4, 2013. pages 131-140, ACM, 2013. [doi]
Abstract is missing.