@Article{	  DieKoptcs12,
  title		= "Language theoretical properties of hairpin formations",
  journal	= "Theoretical Computer Science",
  volume	= "429",
  pages		= "65--73",
  year		= "2012",
  note		= "Magic in Science: {S}pecial issue dedicated to the 70th
		  birthday of {G}rzegorz {R}ozenberg",
  issn		= "0304-3975",
  doi		= "10.1016/j.tcs.2011.12.025",
  url		= "http://www.sciencedirect.com/science/article/pii/S0304397511009911",
  author	= "Volker Diekert and Steffen Kopecki",
  keywords	= "Varieties"
}