@InProceedings{	  die88,
  author	= "Volker Diekert",
  address	= "Heidelberg",
  booktitle	= "Proc. 15th International Colloquium Automata, Languages
		  and Programming (ICALP'88), Tampere",
  editor	= "T. Lepist{\"o} and others",
  volume	= "317",
  pages		= "176--187",
  publisher	= "Springer-Verlag",
  series	= "Lecture Notes in Computer Science",
  title		= "Transitive orientations, {M\"o}bius functions and complete
		  semi-{T}hue systems for free partially commutative monoids",
  year		= "1988",
  doi		= "10.1007/3-540-19488-6_115"
}