Giovanni Pighizzini. Unary Pushdown Automata and Auxiliary Space Lower Bounds. In Mogens Nielsen, Branislav Rovan, editors, Mathematical Foundations of Computer Science 2000, 25th International Symposium, MFCS 2000, Bratislava, Slovakia, August 28 - September 1, 2000, Proceedings. Volume 1893 of Lecture Notes in Computer Science, pages 599-608, Springer, 2000. [doi]
Abstract is missing.