Klaus-Jörn Lange Are There Formal Languages Complete for SymSPACE(log n)? 125-134 http://link.springer.de/link/service/series/0558/bibs/1337/13370125.htm 1997 conf/birthday/1997brauer Foundations of Computer Science: Potential - Theory - Cognition db/conf/birthday/brauer97.html#Lange97