@Article{	  die93concat,
  author	= "Volker Diekert",
  journal	= "Theoretical Computer Science",
  note		= "Special issue STACS'91",
  pages		= "35--54",
  title		= "On the concatenation of infinite traces",
  volume	= "113",
  year		= "1993",
  doi		= "10.1016/0304-3975(93)90209-C"
}