@InProceedings{	  die89,
  author	= "Volker Diekert",
  address	= "Heidelberg",
  booktitle	= "Proc. 6th Annual Symposium on Theoretical Aspects of
		  Computer Science (STACS 1989), Paderborn (Germany)",
  editor	= "B. Monien and others",
  note		= "Revised and extended version in \cite{die90tcs},
		  Theoretical Computer Science 74 (1990) 3-18",
  volume	= "349",
  pages		= "168--180",
  publisher	= "Springer-Verlag",
  series	= "Lecture Notes in Computer Science",
  title		= "Word problems over traces which are solvable in linear
		  time",
  year		= "1989",
  doi		= "10.1007/BFb0028982"
}