@Proceedings{	  dh06tcs,
  title		= "Theory of Computing Systems: Special Issue of the 21st
		  International Symposium on Theoretical Aspects of Computer
		  Science (STACS'04), Montpellier 2004, Proceedings",
  journal	= "Theory of Computing Systems",
  year		= "2006",
  volume	= "39",
  number	= "1",
  pages		= "1",
  editor	= "Volker Diekert and Michael Habib",
  publisher	= "Springer",
  doi		= "10.1007/s00224-005-3902-7",
  author	= "Diekert, Volker and Habib, Michel"
}